Merge branch 'dev' into agent/Rex/CUB-130-add-edit-filament-form

Reviewed-on: #42

backend/Dockerfile

@@ -1,37 +1,25 @@
-# ── Stage 1: Build ──────────────────────────────────────────
-FROM mcr.microsoft.com/dotnet/sdk:9.0 AS build
-WORKDIR /src
+# Build stage
+FROM golang:1.24-alpine AS builder
 
-# Copy csproj first for layer caching — restores before copying source
-COPY Extrudex.csproj .
-RUN dotnet restore
-
-# Copy the rest of the source
-COPY . .
-RUN dotnet publish Extrudex.csproj \
-    -c Release \
-    -o /app/publish \
-    --no-restore
-
-# ── Stage 2: Runtime ────────────────────────────────────────
-FROM mcr.microsoft.com/dotnet/aspnet:9.0 AS runtime
 WORKDIR /app
 
-# Install curl for health check (not included in aspnet base image)
-RUN apt-get update && apt-get install -y --no-install-recommends curl && rm -rf /var/lib/apt/lists/*
+# Copy go mod files first for caching
+COPY go.mod go.sum ./
+RUN go mod download
 
-# Non-root user for security
-RUN adduser --disabled-password --gecos "" appuser
-USER appuser
+# Copy source and build
+COPY . .
+RUN CGO_ENABLED=0 GOOS=linux go build -o server ./cmd/server
 
-# Copy published output from build stage
-COPY --from=build /app/publish .
+# Final stage
+FROM alpine:latest
+RUN apk --no-cache add ca-certificates
+
+WORKDIR /root/
+
+# Copy binary from builder
+COPY --from=builder /app/server .
 
-# ASP.NET Core listens on 8080 by default in .NET 8+
 EXPOSE 8080
 
-# Health check against /health endpoint
-HEALTHCHECK --interval=30s --timeout=5s --start-period=10s --retries=3 \
-    CMD curl --fail http://localhost:8080/health || exit 1
-
-ENTRYPOINT ["dotnet", "Extrudex.dll"]
+CMD ["./server"]

backend/Domain/Interfaces/IFilamentUsageService.cs

@@ -0,0 +1,50 @@
+using Extrudex.Domain.Entities;
+
+namespace Extrudex.Domain.Interfaces;
+
+/// <summary>
+/// Service for persisting and querying filament usage records.
+/// Tracks consumption per print job and per spool for COGS and inventory tracking.
+/// </summary>
+public interface IFilamentUsageService
+{
+    /// <summary>
+    /// Records a new filament usage entry for a print job.
+    /// </summary>
+    /// <param name="printJobId">The print job that consumed the filament.</param>
+    /// <param name="spoolId">The spool that provided the filament.</param>
+    /// <param name="printerId">The printer that executed the print.</param>
+    /// <param name="gramsUsed">Grams of filament consumed.</param>
+    /// <param name="mmExtruded">Millimeters of filament extruded.</param>
+    /// <param name="notes">Optional notes about this usage record.</param>
+    /// <param name="cancellationToken">Cancellation token.</param>
+    /// <returns>The created FilamentUsage entity.</returns>
+    Task<FilamentUsage> RecordUsageAsync(
+        Guid printJobId,
+        Guid spoolId,
+        Guid printerId,
+        decimal gramsUsed,
+        decimal mmExtruded,
+        string? notes = null,
+        CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Retrieves all filament usage records for a specific print job.
+    /// </summary>
+    /// <param name="printJobId">The print job ID.</param>
+    /// <param name="cancellationToken">Cancellation token.</param>
+    /// <returns>Collection of filament usage records for the print job.</returns>
+    Task<IReadOnlyList<FilamentUsage>> GetByPrintJobAsync(
+        Guid printJobId,
+        CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Retrieves all filament usage records for a specific spool.
+    /// </summary>
+    /// <param name="spoolId">The spool ID.</param>
+    /// <param name="cancellationToken">Cancellation token.</param>
+    /// <returns>Collection of filament usage records for the spool.</returns>
+    Task<IReadOnlyList<FilamentUsage>> GetBySpoolAsync(
+        Guid spoolId,
+        CancellationToken cancellationToken = default);
+}

backend/Infrastructure/Services/FilamentUsageService.cs

@@ -0,0 +1,79 @@
+using Extrudex.Domain.Entities;
+using Extrudex.Domain.Interfaces;
+using Extrudex.Infrastructure.Data;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Logging;
+
+namespace Extrudex.Infrastructure.Services;
+
+/// <summary>
+/// EF Core–backed implementation of the filament usage service.
+/// Persists usage records to the database and provides query methods
+/// for retrieving usage by print job or spool.
+/// </summary>
+public class FilamentUsageService : IFilamentUsageService
+{
+    private readonly ExtrudexDbContext _dbContext;
+    private readonly ILogger<FilamentUsageService> _logger;
+
+    public FilamentUsageService(
+        ExtrudexDbContext dbContext,
+        ILogger<FilamentUsageService> logger)
+    {
+        _dbContext = dbContext;
+        _logger = logger;
+    }
+
+    /// <inheritdoc />
+    public async Task<FilamentUsage> RecordUsageAsync(
+        Guid printJobId,
+        Guid spoolId,
+        Guid printerId,
+        decimal gramsUsed,
+        decimal mmExtruded,
+        string? notes = null,
+        CancellationToken cancellationToken = default)
+    {
+        var usage = new FilamentUsage
+        {
+            PrintJobId = printJobId,
+            SpoolId = spoolId,
+            PrinterId = printerId,
+            GramsUsed = gramsUsed,
+            MmExtruded = mmExtruded,
+            RecordedAt = DateTime.UtcNow,
+            Notes = notes
+        };
+
+        _dbContext.FilamentUsages.Add(usage);
+        await _dbContext.SaveChangesAsync(cancellationToken);
+
+        _logger.LogInformation(
+            "Recorded filament usage: {Grams}g / {Mm}mm for print job {JobId} on spool {SpoolId}",
+            gramsUsed, mmExtruded, printJobId, spoolId);
+
+        return usage;
+    }
+
+    /// <inheritdoc />
+    public async Task<IReadOnlyList<FilamentUsage>> GetByPrintJobAsync(
+        Guid printJobId,
+        CancellationToken cancellationToken = default)
+    {
+        return await _dbContext.FilamentUsages
+            .Where(u => u.PrintJobId == printJobId)
+            .OrderByDescending(u => u.RecordedAt)
+            .ToListAsync(cancellationToken);
+    }
+
+    /// <inheritdoc />
+    public async Task<IReadOnlyList<FilamentUsage>> GetBySpoolAsync(
+        Guid spoolId,
+        CancellationToken cancellationToken = default)
+    {
+        return await _dbContext.FilamentUsages
+            .Where(u => u.SpoolId == spoolId)
+            .OrderByDescending(u => u.RecordedAt)
+            .ToListAsync(cancellationToken);
+    }
+}

backend/Infrastructure/Services/MoonrakerUsagePoller.cs

@@ -0,0 +1,390 @@
+using Extrudex.Domain.DTOs.Moonraker;
+using Extrudex.Domain.Entities;
+using Extrudex.Domain.Enums;
+using Extrudex.Domain.Interfaces;
+using Extrudex.Infrastructure.Data;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+
+namespace Extrudex.Infrastructure.Services;
+
+/// <summary>
+/// Configuration options for the Moonraker usage polling service.
+/// </summary>
+public class MoonrakerPollerOptions
+{
+    /// <summary>
+    /// How often to poll each Moonraker printer for filament usage data.
+    /// Default: 30 seconds.
+    /// </summary>
+    public TimeSpan PollInterval { get; set; } = TimeSpan.FromSeconds(30);
+
+    /// <summary>
+    /// Timeout for individual Moonraker HTTP requests.
+    /// Default: 10 seconds.
+    /// </summary>
+    public TimeSpan RequestTimeout { get; set; } = TimeSpan.FromSeconds(10);
+
+    /// <summary>
+    /// Whether the polling service is enabled. Default: true.
+    /// Set to false to disable polling (e.g., in development or testing).
+    /// </summary>
+    public bool Enabled { get; set; } = true;
+}
+
+/// <summary>
+/// Background service that periodically polls Moonraker-connected printers
+/// for filament usage data. When a print job is detected as complete,
+/// the usage data is persisted to the FilamentUsage table via
+/// <see cref="IFilamentUsageService"/>.
+///
+/// <para>Polling logic:</para>
+/// <list type="number">
+///   <item>Query the database for all active printers with ConnectionType == Moonraker.</item>
+///   <item>For each printer, call <see cref="IMoonrakerClient.GetPrintStatsAsync"/> for live data
+///         and <see cref="IMoonrakerClient.GetPrintHistoryAsync"/> for completed job history.</item>
+///   <item>If usage data is available and the print state is "complete",
+///         create or update a FilamentUsage record.</item>
+///   <item>If the printer is unreachable or returns malformed data, log a warning
+///         and continue to the next printer (no crash).</item>
+/// </list>
+///
+/// <para>Error handling:</para>
+/// <list type="bullet">
+///   <item>API unreachable: logged as warning, poller continues for other printers.</item>
+///   <item>Malformed response: logged as warning, poller continues.</item>
+///   <item>Database errors: logged as error, poller continues.</item>
+/// </list>
+/// </summary>
+public class MoonrakerUsagePoller : BackgroundService
+{
+    private readonly IServiceScopeFactory _scopeFactory;
+    private readonly ILogger<MoonrakerUsagePoller> _logger;
+    private readonly MoonrakerPollerOptions _options;
+
+    /// <summary>
+    /// Tracks which Moonraker print jobs have already been recorded,
+    /// keyed by "printerId:gcodeFileName" to avoid duplicate recording.
+    /// </summary>
+    private readonly HashSet<string> _recordedJobs = new();
+
+    public MoonrakerUsagePoller(
+        IServiceScopeFactory scopeFactory,
+        ILogger<MoonrakerUsagePoller> logger,
+        IOptions<MoonrakerPollerOptions> options)
+    {
+        _scopeFactory = scopeFactory;
+        _logger = logger;
+        _options = options.Value;
+    }
+
+    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
+    {
+        if (!_options.Enabled)
+        {
+            _logger.LogInformation("Moonraker usage poller is disabled via configuration.");
+            return;
+        }
+
+        _logger.LogInformation(
+            "Moonraker usage poller starting. Poll interval: {Interval}",
+            _options.PollInterval);
+
+        while (!stoppingToken.IsCancellationRequested)
+        {
+            try
+            {
+                await PollAllPrintersAsync(stoppingToken);
+            }
+            catch (Exception ex)
+            {
+                _logger.LogError(ex,
+                    "Unexpected error in Moonraker usage poller cycle. Continuing.");
+            }
+
+            await Task.Delay(_options.PollInterval, stoppingToken);
+        }
+
+        _logger.LogInformation("Moonraker usage poller stopping.");
+    }
+
+    private async Task PollAllPrintersAsync(CancellationToken cancellationToken)
+    {
+        using var scope = _scopeFactory.CreateScope();
+        var dbContext = scope.ServiceProvider.GetRequiredService<ExtrudexDbContext>();
+        var moonrakerClient = scope.ServiceProvider.GetRequiredService<IMoonrakerClient>();
+        var usageService = scope.ServiceProvider.GetRequiredService<IFilamentUsageService>();
+
+        var printers = await dbContext.Printers
+            .Where(p => p.IsActive && p.ConnectionType == ConnectionType.Moonraker)
+            .ToListAsync(cancellationToken);
+
+        if (printers.Count == 0)
+        {
+            _logger.LogDebug("No active Moonraker printers found.");
+            return;
+        }
+
+        _logger.LogDebug("Polling {Count} Moonraker printer(s).", printers.Count);
+
+        foreach (var printer in printers)
+        {
+            await PollPrinterAsync(
+                printer, moonrakerClient, usageService, dbContext, cancellationToken);
+        }
+    }
+
+    private async Task PollPrinterAsync(
+        Printer printer,
+        IMoonrakerClient moonrakerClient,
+        IFilamentUsageService usageService,
+        ExtrudexDbContext dbContext,
+        CancellationToken cancellationToken)
+    {
+        _logger.LogDebug(
+            "Polling Moonraker printer {PrinterName} ({Host}:{Port})",
+            printer.Name, printer.HostnameOrIp, printer.Port);
+
+        try
+        {
+            var printStats = await moonrakerClient.GetPrintStatsAsync(
+                printer.HostnameOrIp,
+                printer.Port,
+                printer.ApiKey,
+                cancellationToken);
+
+            if (printStats is null)
+            {
+                _logger.LogDebug(
+                    "No print stats available from printer {PrinterName}.", printer.Name);
+                return;
+            }
+
+            printer.LastSeenAt = DateTime.UtcNow;
+            await dbContext.SaveChangesAsync(cancellationToken);
+
+            _logger.LogDebug(
+                "Printer {PrinterName}: state={State}, filament={Mm}mm, file={File}",
+                printer.Name, printStats.State, printStats.FilamentUsedMm, printStats.Filename);
+
+            decimal mmExtruded = printStats.FilamentUsedMm;
+            if (mmExtruded <= 0)
+            {
+                _logger.LogDebug(
+                    "Printer {PrinterName} has no filament usage to record.", printer.Name);
+                return;
+            }
+
+            if (!IsCompleteState(printStats.State))
+            {
+                _logger.LogDebug(
+                    "Printer {PrinterName} print state '{State}' is not complete; skipping.",
+                    printer.Name, printStats.State);
+                return;
+            }
+
+            string gcodeFileName = printStats.Filename ?? $"unknown-{Guid.NewGuid():N}";
+            var deduplicationKey = $"{printer.Id}:{gcodeFileName}";
+            if (_recordedJobs.Contains(deduplicationKey))
+            {
+                _logger.LogDebug(
+                    "Printer {PrinterName} job '{File}' already recorded; skipping.",
+                    printer.Name, gcodeFileName);
+                return;
+            }
+
+            DateTime? startedAt = null;
+            DateTime? completedAt = null;
+            try
+            {
+                var history = await moonrakerClient.GetPrintHistoryAsync(
+                    printer.HostnameOrIp, printer.Port, printer.ApiKey,
+                    limit: 1, cancellationToken);
+
+                if (history.Items.Count > 0)
+                {
+                    var latestJob = history.Items[0];
+                    startedAt = latestJob.StartTime;
+                    completedAt = latestJob.EndTime;
+                }
+            }
+            catch (Exception ex)
+            {
+                _logger.LogDebug(ex,
+                    "Could not fetch history for printer {PrinterName}; proceeding with stats only.",
+                    printer.Name);
+            }
+
+            var printJob = await FindOrCreatePrintJobAsync(
+                dbContext, printer, mmExtruded, gcodeFileName,
+                startedAt, completedAt, cancellationToken);
+
+            if (printJob is null)
+            {
+                _logger.LogWarning(
+                    "Could not find or create print job for printer {PrinterName}. No active spool found.",
+                    printer.Name);
+                return;
+            }
+
+            var spool = await dbContext.Spools.FindAsync(
+                new object[] { printJob.SpoolId }, cancellationToken);
+
+            var gramsUsed = CalculateGramsUsed(mmExtruded, spool);
+
+            await usageService.RecordUsageAsync(
+                printJobId: printJob.Id,
+                spoolId: printJob.SpoolId,
+                printerId: printer.Id,
+                gramsUsed: gramsUsed,
+                mmExtruded: mmExtruded,
+                notes: $"Moonraker auto-recorded: {gcodeFileName}",
+                cancellationToken: cancellationToken);
+
+            _recordedJobs.Add(deduplicationKey);
+
+            _logger.LogInformation(
+                "Recorded Moonraker usage for printer {PrinterName}: {Mm}mm / {Grams}g, job '{File}'",
+                printer.Name, mmExtruded, gramsUsed, gcodeFileName);
+        }
+        catch (HttpRequestException ex)
+        {
+            _logger.LogWarning(ex,
+                "Moonraker API unreachable for printer {PrinterName} ({Host}:{Port}). Will retry next cycle.",
+                printer.Name, printer.HostnameOrIp, printer.Port);
+        }
+        catch (TaskCanceledException) when (cancellationToken.IsCancellationRequested)
+        {
+            throw;
+        }
+        catch (TaskCanceledException ex)
+        {
+            _logger.LogWarning(ex,
+                "Moonraker request timed out for printer {PrinterName} ({Host}:{Port}).",
+                printer.Name, printer.HostnameOrIp, printer.Port);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex,
+                "Unexpected error polling Moonraker printer {PrinterName}. Continuing to next printer.",
+                printer.Name);
+        }
+    }
+
+    private static bool IsCompleteState(string state) =>
+        state.Equals("complete", StringComparison.OrdinalIgnoreCase) ||
+        state.Equals("completed", StringComparison.OrdinalIgnoreCase);
+
+    private async Task<PrintJob?> FindOrCreatePrintJobAsync(
+        ExtrudexDbContext dbContext,
+        Printer printer,
+        decimal mmExtruded,
+        string gcodeFileName,
+        DateTime? startedAt,
+        DateTime? completedAt,
+        CancellationToken cancellationToken)
+    {
+        if (!string.IsNullOrEmpty(gcodeFileName))
+        {
+            var existingJob = await dbContext.PrintJobs
+                .Where(j => j.PrinterId == printer.Id &&
+                            j.GcodeFilePath == gcodeFileName &&
+                            j.DataSource == DataSource.Moonraker &&
+                            j.Status != JobStatus.Cancelled)
+                .OrderByDescending(j => j.CreatedAt)
+                .FirstOrDefaultAsync(cancellationToken);
+
+            if (existingJob is not null)
+            {
+                existingJob.MmExtruded = mmExtruded;
+                existingJob.GramsDerived = CalculateGramsUsed(
+                    mmExtruded,
+                    await dbContext.Spools.FindAsync(
+                        new object[] { existingJob.SpoolId }, cancellationToken));
+                existingJob.Status = JobStatus.Completed;
+                existingJob.CompletedAt = completedAt ?? DateTime.UtcNow;
+                existingJob.StartedAt ??= startedAt;
+                await dbContext.SaveChangesAsync(cancellationToken);
+                return existingJob;
+            }
+        }
+
+        var spool = await FindActiveSpoolForPrinterAsync(dbContext, printer, cancellationToken);
+        if (spool is null) return null;
+
+        var gramsDerived = CalculateGramsUsed(mmExtruded, spool);
+
+        var newJob = new PrintJob
+        {
+            PrinterId = printer.Id,
+            SpoolId = spool.Id,
+            PrintName = gcodeFileName ?? "Moonraker Print",
+            GcodeFilePath = gcodeFileName,
+            MmExtruded = mmExtruded,
+            GramsDerived = gramsDerived,
+            FilamentDiameterAtPrintMm = spool.FilamentDiameterMm,
+            MaterialDensityAtPrint = GetMaterialDensity(spool),
+            DataSource = DataSource.Moonraker,
+            Status = JobStatus.Completed,
+            StartedAt = startedAt ?? DateTime.UtcNow,
+            CompletedAt = completedAt ?? DateTime.UtcNow,
+            Notes = "Auto-created by Moonraker usage poller"
+        };
+
+        dbContext.PrintJobs.Add(newJob);
+        await dbContext.SaveChangesAsync(cancellationToken);
+
+        return newJob;
+    }
+
+    private static async Task<Spool?> FindActiveSpoolForPrinterAsync(
+        ExtrudexDbContext dbContext,
+        Printer printer,
+        CancellationToken cancellationToken)
+    {
+        var amsSpool = await dbContext.AmsSlots
+            .Include(s => s.Spool)
+            .ThenInclude(s => s!.MaterialBase)
+            .Include(s => s.AmsUnit)
+            .Where(s => s.AmsUnit.PrinterId == printer.Id && s.Spool != null && s.Spool.IsActive)
+            .Select(s => s.Spool)
+            .FirstOrDefaultAsync(cancellationToken);
+
+        if (amsSpool is not null) return amsSpool;
+
+        return await dbContext.Spools
+            .Include(s => s.MaterialBase)
+            .Where(s => s.IsActive)
+            .OrderByDescending(s => s.WeightRemainingGrams)
+            .FirstOrDefaultAsync(cancellationToken);
+    }
+
+    private static decimal CalculateGramsUsed(decimal mmExtruded, Spool? spool)
+    {
+        if (spool is null) return 0m;
+        var diameterMm = spool.FilamentDiameterMm;
+        var densityGcm3 = GetMaterialDensity(spool);
+        var radiusMm = diameterMm / 2m;
+        var crossSectionArea = Math.PI * (double)radiusMm * (double)radiusMm;
+        var volumeMm3 = (double)mmExtruded * crossSectionArea;
+        var volumeCm3 = volumeMm3 / 1000.0;
+        var grams = volumeCm3 * (double)densityGcm3;
+        return Math.Round((decimal)grams, 2);
+    }
+
+    private static decimal GetMaterialDensity(Spool? spool)
+    {
+        return spool?.MaterialBase?.Name?.ToUpperInvariant() switch
+        {
+            "PLA" => 1.24m,
+            "PETG" => 1.27m,
+            "ABS" => 1.04m,
+            "ASA" => 1.07m,
+            "TPU" => 1.21m,
+            "NYLON" or "PA" => 1.13m,
+            "PC" => 1.20m,
+            _ => 1.24m
+        };
+    }
+}

backend/Program.cs

@@ -61,6 +61,14 @@ builder.Services.AddSingleton<ILowStockDetector, LowStockDetector>();
 // ── Usage Logging ───────────────────────────────────────────
 builder.Services.AddScoped<IUsageLogService, UsageLogService>();
 
+// ── Filament Usage Service ──────────────────────────────────
+builder.Services.AddScoped<IFilamentUsageService, FilamentUsageService>();
+
+// ── Moonraker Usage Poller (Background Service) ─────────────
+builder.Services.Configure<MoonrakerPollerOptions>(
+    builder.Configuration.GetSection("MoonrakerPoller"));
+builder.Services.AddHostedService<MoonrakerUsagePoller>();
+
 // ── FluentValidation ──────────────────────────────────────
 // Registers all validators from the API assembly into DI.
 builder.Services.AddValidatorsFromAssembly(Assembly.GetExecutingAssembly());

backend/appsettings.json

@@ -23,5 +23,11 @@
   },
   "FilamentAlerts": {
     "LowStockThresholdPercent": 20
+  },
+  "MoonrakerPoller": {
+    "Enabled": true,
+    "PollInterval": "00:00:30",
+    "RequestTimeout": "00:00:10"
   }
+}
 }

backend/cmd/server/main.go

@@ -0,0 +1,90 @@
+package main
+
+import (
+	"context"
+	"log/slog"
+	"net/http"
+	"os"
+	"os/signal"
+	"syscall"
+	"time"
+
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/config"
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/db"
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/router"
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/sse"
+)
+
+func main() {
+	// Setup structured logging
+	slog.SetDefault(slog.New(slog.NewTextHandler(os.Stdout, &slog.HandlerOptions{
+		Level: slog.LevelInfo,
+	})))
+
+	// Load configuration
+	cfg, err := config.Load()
+	if err != nil {
+		slog.Error("failed to load config", "error", err)
+		os.Exit(1)
+	}
+
+	slog.Info("config loaded", "port", cfg.Port, "cors_origin", cfg.CorsOrigin)
+
+	// Connect to database
+	dbPool, err := db.NewPool(cfg.DatabaseURL)
+	if err != nil {
+		slog.Error("failed to connect to database", "error", err)
+		os.Exit(1)
+	}
+	defer db.ClosePool(dbPool)
+
+	slog.Info("database connected")
+
+	// Create SSE broadcaster and start it
+	sseBC := sse.NewBroadcaster(128)
+	sseBC.Start()
+	defer sseBC.Stop()
+
+	slog.Info("sse broadcaster started")
+
+	// Create router
+	r := router.New(cfg, dbPool, sseBC)
+
+	// Create HTTP server
+	// WriteTimeout is 0 for SSE support — the Chi middleware.Timeout(60s)
+	// handles request-level timeouts on non-SSE routes.
+	server := &http.Server{
+		Addr:         ":" + cfg.Port,
+		Handler:      r,
+		ReadTimeout:  15 * time.Second,
+		WriteTimeout: 0, // disabled for SSE long-lived connections
+		IdleTimeout:  60 * time.Second,
+	}
+
+	// Start server in goroutine
+	go func() {
+		slog.Info("server starting", "addr", server.Addr)
+		if err := server.ListenAndServe(); err != nil && err != http.ErrServerClosed {
+			slog.Error("server error", "error", err)
+			os.Exit(1)
+		}
+	}()
+
+	// Wait for shutdown signal
+	quit := make(chan os.Signal, 1)
+	signal.Notify(quit, syscall.SIGINT, syscall.SIGTERM)
+	<-quit
+
+	slog.Info("server shutting down")
+
+	// Graceful shutdown
+	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	defer cancel()
+
+	if err := server.Shutdown(ctx); err != nil {
+		slog.Error("server shutdown error", "error", err)
+	}
+
+	db.ClosePool(dbPool)
+	slog.Info("server stopped")
+}

backend/go.mod

@@ -0,0 +1,18 @@
+module github.com/CubeCraft-Creations/Extrudex/backend
+
+go 1.24
+
+require (
+	github.com/go-chi/chi/v5 v5.2.0
+	github.com/jackc/pgx/v5 v5.7.4
+	github.com/kelseyhightower/envconfig v1.4.0
+)
+
+require (
+	github.com/jackc/pgpassfile v1.0.0 // indirect
+	github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 // indirect
+	github.com/jackc/puddle/v2 v2.2.2 // indirect
+	golang.org/x/crypto v0.31.0 // indirect
+	golang.org/x/sync v0.10.0 // indirect
+	golang.org/x/text v0.21.0 // indirect
+)

backend/go.sum

@@ -0,0 +1,32 @@
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/go-chi/chi/v5 v5.2.0 h1:Aj1EtB0qR2Rdo2dG4O94RIU35w2lvQSj6BRA4+qwFL0=
+github.com/go-chi/chi/v5 v5.2.0/go.mod h1:DslCQbL2OYiznFReuXYUmQ2hGd1aDpCnlMNITLSKoi8=
+github.com/jackc/pgpassfile v1.0.0 h1:/6Hmqy13Ss2zCq62VdNG8tM1wchn8zjSGOBJ6icpsIM=
+github.com/jackc/pgpassfile v1.0.0/go.mod h1:CEx0iS5ambNFdcRtxPj5JhEz+xB6uRky5eyVu/W2HEg=
+github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 h1:iCEnooe7UlwOQYpKFhBabPMi4aNAfoODPEFNiAnClxo=
+github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761/go.mod h1:5TJZWKEWniPve33vlWYSoGYefn3gLQRzjfDlhSJ9ZKM=
+github.com/jackc/pgx/v5 v5.7.4 h1:9wKznZrhWa2QiHL+NjTSPP6yjl3451BX3imWDnokYlg=
+github.com/jackc/pgx/v5 v5.7.4/go.mod h1:ncY89UGWxg82EykZUwSpUKEfccBGGYq1xjrOpsbsfGQ=
+github.com/jackc/puddle/v2 v2.2.2 h1:PR8nw+E/1w0GLuRFSmiioY6UooMp6KJv0/61nB7icHo=
+github.com/jackc/puddle/v2 v2.2.2/go.mod h1:vriiEXHvEE654aYKXXjOvZM39qJ0q+azkZFrfEOc3H4=
+github.com/kelseyhightower/envconfig v1.4.0 h1:Im6hONhd3pLkfDFsbRgu68RDNkGF1r3dvMUtDTo2cv8=
+github.com/kelseyhightower/envconfig v1.4.0/go.mod h1:cccZRl6mQpaq41TPp5QxidR+Sa3axMbJDNb//FQX6Gg=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
+github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/stretchr/testify v1.8.1 h1:w7B6lhMri9wdJUVmEZPGGhZzrYTPvgJArz7wNPgYKsk=
+github.com/stretchr/testify v1.8.1/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
+golang.org/x/crypto v0.31.0 h1:ihbySMvVjLAeSH1IbfcRTkD/iNscyz8rGzjF/E5hV6U=
+golang.org/x/crypto v0.31.0/go.mod h1:kDsLvtWBEx7MV9tJOj9bnXsPbxwJQ6csT/x4KIN4Ssk=
+golang.org/x/sync v0.10.0 h1:3NQrjDixjgGwUOCaF8w2+VYHv0Ve/vGYSbdkTa98gmQ=
+golang.org/x/sync v0.10.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
+golang.org/x/text v0.21.0 h1:zyQAAkrwaneQ066sspRyJaG9VNi/YJ1NfzcGB3hZ/qo=
+golang.org/x/text v0.21.0/go.mod h1:4IBbMaMmOPCJ8SecivzSH54+73PCFmPWxNTLm+vZkEQ=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

backend/internal/config/config.go

@@ -0,0 +1,24 @@
+package config
+
+import (
+	"fmt"
+
+	"github.com/kelseyhightower/envconfig"
+)
+
+// Config holds all application configuration loaded from environment variables.
+type Config struct {
+	DatabaseURL string `envconfig:"database_url" required:"true"`
+	Port        string `envconfig:"port" default:"8080"`
+	CorsOrigin  string `envconfig:"cors_origin" default:"*"`
+	LogLevel    string `envconfig:"log_level" default:"info"`
+}
+
+// Load reads configuration from environment variables and returns a populated Config.
+func Load() (*Config, error) {
+	var cfg Config
+	if err := envconfig.Process("", &cfg); err != nil {
+		return nil, fmt.Errorf("failed to load config: %w", err)
+	}
+	return &cfg, nil
+}

backend/internal/db/db.go

@@ -0,0 +1,34 @@
+package db
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+// NewPool creates a new pgx connection pool and verifies connectivity with a ping.
+func NewPool(databaseURL string) (*pgxpool.Pool, error) {
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+
+	pool, err := pgxpool.New(ctx, databaseURL)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create db pool: %w", err)
+	}
+
+	if err := pool.Ping(ctx); err != nil {
+		pool.Close()
+		return nil, fmt.Errorf("failed to ping db: %w", err)
+	}
+
+	return pool, nil
+}
+
+// ClosePool gracefully closes the connection pool.
+func ClosePool(pool *pgxpool.Pool) {
+	if pool != nil {
+		pool.Close()
+	}
+}

backend/internal/dtos/dtos.go

@@ -0,0 +1,67 @@
+// Package dtos defines request/response data transfer objects for the Extrudex API.
+// DTOs keep HTTP serialization concerns separate from domain models.
+package dtos
+
+// ============================================================================
+// Common Response Wrappers
+// ============================================================================
+
+// ListResponse wraps a paginated collection response.
+type ListResponse struct {
+	Data   any `json:"data"`
+	Total  int `json:"total"`
+	Limit  int `json:"limit"`
+	Offset int `json:"offset"`
+}
+
+// SingleResponse wraps a single-item response.
+type SingleResponse struct {
+	Data any `json:"data"`
+}
+
+// ErrorResponse is the standard error payload for all API errors.
+type ErrorResponse struct {
+	Error string `json:"error"`
+	Code  int    `json:"code"`
+}
+
+// ============================================================================
+// Filament DTOs
+// ============================================================================
+
+// CreateFilamentRequest is the POST body for creating a new filament spool.
+type CreateFilamentRequest struct {
+	Name                  string  `json:"name"`
+	MaterialBaseID        int     `json:"material_base_id"`
+	MaterialFinishID      int     `json:"material_finish_id"`
+	MaterialModifierID    *int    `json:"material_modifier_id,omitempty"`
+	ColorHex             string  `json:"color_hex"`
+	Brand                *string `json:"brand,omitempty"`
+	DiameterMM           *float64 `json:"diameter_mm,omitempty"` // defaults to 1.75
+	InitialGrams         int     `json:"initial_grams"`
+	RemainingGrams       int     `json:"remaining_grams"`
+	SpoolWeightGrams     *int    `json:"spool_weight_grams,omitempty"`
+	CostUSD              *float64 `json:"cost_usd,omitempty"`
+	LowStockThresholdGrams *int  `json:"low_stock_threshold_grams,omitempty"` // defaults to 50
+	Notes                *string `json:"notes,omitempty"`
+	Barcode              *string `json:"barcode,omitempty"`
+}
+
+// UpdateFilamentRequest is the PUT body for partially updating a filament spool.
+// All fields are optional — only non-nil fields are applied.
+type UpdateFilamentRequest struct {
+	Name                  *string  `json:"name,omitempty"`
+	MaterialBaseID        *int     `json:"material_base_id,omitempty"`
+	MaterialFinishID      *int     `json:"material_finish_id,omitempty"`
+	MaterialModifierID    *int     `json:"material_modifier_id,omitempty"`
+	ColorHex             *string  `json:"color_hex,omitempty"`
+	Brand                *string  `json:"brand,omitempty"`
+	DiameterMM           *float64 `json:"diameter_mm,omitempty"`
+	InitialGrams         *int     `json:"initial_grams,omitempty"`
+	RemainingGrams       *int     `json:"remaining_grams,omitempty"`
+	SpoolWeightGrams     *int     `json:"spool_weight_grams,omitempty"`
+	CostUSD              *float64 `json:"cost_usd,omitempty"`
+	LowStockThresholdGrams *int   `json:"low_stock_threshold_grams,omitempty"`
+	Notes                *string  `json:"notes,omitempty"`
+	Barcode              *string  `json:"barcode,omitempty"`
+}

backend/internal/handlers/filament_handler.go

@@ -0,0 +1,273 @@
+package handlers
+
+import (
+	"encoding/json"
+	"log/slog"
+	"net/http"
+	"strconv"
+
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/dtos"
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/models"
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/repositories"
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/services"
+	"github.com/go-chi/chi/v5"
+)
+
+// FilamentHandler handles HTTP requests for filament spool CRUD operations.
+type FilamentHandler struct {
+	service *services.FilamentService
+}
+
+// NewFilamentHandler creates a FilamentHandler with the given service.
+func NewFilamentHandler(service *services.FilamentService) *FilamentHandler {
+	return &FilamentHandler{service: service}
+}
+
+// List handles GET /api/filaments — returns paginated, filtered spools.
+func (h *FilamentHandler) List(w http.ResponseWriter, r *http.Request) {
+	limit, offset := parsePagination(r)
+	filter := repositories.FilamentFilter{
+		Material: r.URL.Query().Get("material"),
+		Finish:   r.URL.Query().Get("finish"),
+		Color:    r.URL.Query().Get("color"),
+		LowStock: r.URL.Query().Get("low_stock") == "true",
+		Limit:    limit,
+		Offset:   offset,
+	}
+
+	spools, total, err := h.service.List(r.Context(), filter)
+	if err != nil {
+		slog.Error("failed to list filaments", "error", err)
+		writeJSON(w, http.StatusInternalServerError, dtos.ErrorResponse{
+			Error: "internal server error",
+			Code:  http.StatusInternalServerError,
+		})
+		return
+	}
+
+	writeJSON(w, http.StatusOK, dtos.ListResponse{
+		Data:   spools,
+		Total:  total,
+		Limit:  limit,
+		Offset: offset,
+	})
+}
+
+// Get handles GET /api/filaments/{id} — returns a single spool.
+func (h *FilamentHandler) Get(w http.ResponseWriter, r *http.Request) {
+	id, err := strconv.Atoi(chi.URLParam(r, "id"))
+	if err != nil {
+		writeJSON(w, http.StatusBadRequest, dtos.ErrorResponse{
+			Error: "invalid filament ID",
+			Code:  http.StatusBadRequest,
+		})
+		return
+	}
+
+	spool, err := h.service.GetByID(r.Context(), id)
+	if err != nil {
+		slog.Error("failed to get filament", "id", id, "error", err)
+		writeJSON(w, http.StatusInternalServerError, dtos.ErrorResponse{
+			Error: "internal server error",
+			Code:  http.StatusInternalServerError,
+		})
+		return
+	}
+	if spool == nil {
+		writeJSON(w, http.StatusNotFound, dtos.ErrorResponse{
+			Error: "filament not found",
+			Code:  http.StatusNotFound,
+		})
+		return
+	}
+
+	writeJSON(w, http.StatusOK, dtos.SingleResponse{Data: spool})
+}
+
+// Create handles POST /api/filaments — creates a new filament spool.
+func (h *FilamentHandler) Create(w http.ResponseWriter, r *http.Request) {
+	var req dtos.CreateFilamentRequest
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		writeJSON(w, http.StatusBadRequest, dtos.ErrorResponse{
+			Error: "invalid request body",
+			Code:  http.StatusBadRequest,
+		})
+		return
+	}
+
+	// Validate required fields.
+	if err := services.ValidateCreateFilamentRequest(req); err != nil {
+		writeJSON(w, http.StatusBadRequest, dtos.ErrorResponse{
+			Error: "validation failed: " + err.Error(),
+			Code:  http.StatusBadRequest,
+		})
+		return
+	}
+
+	// Build domain model.
+	spool := models.FilamentSpool{
+		Name:                  req.Name,
+		MaterialBaseID:        req.MaterialBaseID,
+		MaterialFinishID:      req.MaterialFinishID,
+		MaterialModifierID:    req.MaterialModifierID,
+		ColorHex:             req.ColorHex,
+		Brand:                req.Brand,
+		DiameterMM:           1.75, // default
+		InitialGrams:         req.InitialGrams,
+		RemainingGrams:       req.RemainingGrams,
+		SpoolWeightGrams:     req.SpoolWeightGrams,
+		CostUSD:              req.CostUSD,
+		LowStockThresholdGrams: 50, // default
+		Notes:                req.Notes,
+		Barcode:              req.Barcode,
+	}
+	if req.DiameterMM != nil {
+		spool.DiameterMM = *req.DiameterMM
+	}
+	if req.LowStockThresholdGrams != nil {
+		spool.LowStockThresholdGrams = *req.LowStockThresholdGrams
+	}
+
+	created, err := h.service.Create(r.Context(), &spool)
+	if err != nil {
+		slog.Error("failed to create filament", "error", err)
+		writeJSON(w, http.StatusInternalServerError, dtos.ErrorResponse{
+			Error: "internal server error",
+			Code:  http.StatusInternalServerError,
+		})
+		return
+	}
+
+	writeJSON(w, http.StatusCreated, dtos.SingleResponse{Data: created})
+}
+
+// Update handles PUT /api/filaments/{id} — partially updates a spool.
+func (h *FilamentHandler) Update(w http.ResponseWriter, r *http.Request) {
+	id, err := strconv.Atoi(chi.URLParam(r, "id"))
+	if err != nil {
+		writeJSON(w, http.StatusBadRequest, dtos.ErrorResponse{
+			Error: "invalid filament ID",
+			Code:  http.StatusBadRequest,
+		})
+		return
+	}
+
+	var req dtos.UpdateFilamentRequest
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		writeJSON(w, http.StatusBadRequest, dtos.ErrorResponse{
+			Error: "invalid request body",
+			Code:  http.StatusBadRequest,
+		})
+		return
+	}
+
+	// Validate update fields.
+	if err := services.ValidateUpdateFilamentRequest(req); err != nil {
+		writeJSON(w, http.StatusBadRequest, dtos.ErrorResponse{
+			Error: "validation failed: " + err.Error(),
+			Code:  http.StatusBadRequest,
+		})
+		return
+	}
+
+	// Build updates map (only non-nil fields).
+	updates := buildFilamentUpdates(req)
+
+	updated, err := h.service.Update(r.Context(), id, updates)
+	if err != nil {
+		slog.Error("failed to update filament", "id", id, "error", err)
+		writeJSON(w, http.StatusInternalServerError, dtos.ErrorResponse{
+			Error: "internal server error",
+			Code:  http.StatusInternalServerError,
+		})
+		return
+	}
+	if updated == nil {
+		writeJSON(w, http.StatusNotFound, dtos.ErrorResponse{
+			Error: "filament not found",
+			Code:  http.StatusNotFound,
+		})
+		return
+	}
+
+	writeJSON(w, http.StatusOK, dtos.SingleResponse{Data: updated})
+}
+
+// Delete handles DELETE /api/filaments/{id} — soft-deletes a spool.
+func (h *FilamentHandler) Delete(w http.ResponseWriter, r *http.Request) {
+	id, err := strconv.Atoi(chi.URLParam(r, "id"))
+	if err != nil {
+		writeJSON(w, http.StatusBadRequest, dtos.ErrorResponse{
+			Error: "invalid filament ID",
+			Code:  http.StatusBadRequest,
+		})
+		return
+	}
+
+	deleted, err := h.service.SoftDelete(r.Context(), id)
+	if err != nil {
+		slog.Error("failed to delete filament", "id", id, "error", err)
+		writeJSON(w, http.StatusInternalServerError, dtos.ErrorResponse{
+			Error: "internal server error",
+			Code:  http.StatusInternalServerError,
+		})
+		return
+	}
+	if !deleted {
+		writeJSON(w, http.StatusNotFound, dtos.ErrorResponse{
+			Error: "filament not found",
+			Code:  http.StatusNotFound,
+		})
+		return
+	}
+
+	w.WriteHeader(http.StatusNoContent)
+}
+
+// buildFilamentUpdates converts an UpdateFilamentRequest to a map of column→value.
+func buildFilamentUpdates(req dtos.UpdateFilamentRequest) map[string]interface{} {
+	updates := make(map[string]interface{})
+	if req.Name != nil {
+		updates["name"] = *req.Name
+	}
+	if req.MaterialBaseID != nil {
+		updates["material_base_id"] = *req.MaterialBaseID
+	}
+	if req.MaterialFinishID != nil {
+		updates["material_finish_id"] = *req.MaterialFinishID
+	}
+	if req.MaterialModifierID != nil {
+		updates["material_modifier_id"] = *req.MaterialModifierID
+	}
+	if req.ColorHex != nil {
+		updates["color_hex"] = *req.ColorHex
+	}
+	if req.Brand != nil {
+		updates["brand"] = *req.Brand
+	}
+	if req.DiameterMM != nil {
+		updates["diameter_mm"] = *req.DiameterMM
+	}
+	if req.InitialGrams != nil {
+		updates["initial_grams"] = *req.InitialGrams
+	}
+	if req.RemainingGrams != nil {
+		updates["remaining_grams"] = *req.RemainingGrams
+	}
+	if req.SpoolWeightGrams != nil {
+		updates["spool_weight_grams"] = *req.SpoolWeightGrams
+	}
+	if req.CostUSD != nil {
+		updates["cost_usd"] = *req.CostUSD
+	}
+	if req.LowStockThresholdGrams != nil {
+		updates["low_stock_threshold_grams"] = *req.LowStockThresholdGrams
+	}
+	if req.Notes != nil {
+		updates["notes"] = *req.Notes
+	}
+	if req.Barcode != nil {
+		updates["barcode"] = *req.Barcode
+	}
+	return updates
+}

backend/internal/handlers/health.go

@@ -0,0 +1,50 @@
+package handlers
+
+import (
+	"context"
+	"encoding/json"
+	"log/slog"
+	"net/http"
+	"time"
+
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+// HealthHandler provides a health check endpoint that verifies database connectivity.
+type HealthHandler struct {
+	dbPool *pgxpool.Pool
+}
+
+// NewHealthHandler creates a new HealthHandler with the given database pool.
+func NewHealthHandler(dbPool *pgxpool.Pool) *HealthHandler {
+	return &HealthHandler{dbPool: dbPool}
+}
+
+// ServeHTTP handles GET /health requests.
+func (h *HealthHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	ctx, cancel := context.WithTimeout(r.Context(), 5*time.Second)
+	defer cancel()
+
+	dbConnected := false
+	if h.dbPool != nil {
+		if err := h.dbPool.Ping(ctx); err == nil {
+			dbConnected = true
+		} else {
+			slog.Warn("health check db ping failed", "error", err)
+		}
+	}
+
+	resp := map[string]any{
+		"status":       "ok",
+		"timestamp":    time.Now().UTC().Format(time.RFC3339),
+		"db_connected": dbConnected,
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	if !dbConnected {
+		w.WriteHeader(http.StatusServiceUnavailable)
+	}
+	if err := json.NewEncoder(w).Encode(resp); err != nil {
+		slog.Error("failed to encode health response", "error", err)
+	}
+}

backend/internal/handlers/helpers.go

@@ -0,0 +1,51 @@
+package handlers
+
+import (
+	"encoding/json"
+	"log/slog"
+	"net/http"
+	"strconv"
+
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/dtos"
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/services"
+)
+
+// writeJSON serializes v as JSON to the response writer with the given status code.
+// Logs an error if encoding fails.
+func writeJSON(w http.ResponseWriter, status int, v interface{}) {
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(status)
+	if err := json.NewEncoder(w).Encode(v); err != nil {
+		slog.Error("failed to encode JSON response", "error", err)
+	}
+}
+
+// parsePagination reads limit and offset query parameters with defaults of 20 and 0.
+func parsePagination(r *http.Request) (limit, offset int) {
+	limit = 20
+	offset = 0
+
+	if l := r.URL.Query().Get("limit"); l != "" {
+		if parsed, err := strconv.Atoi(l); err == nil && parsed > 0 {
+			limit = parsed
+		}
+	}
+	if o := r.URL.Query().Get("offset"); o != "" {
+		if parsed, err := strconv.Atoi(o); err == nil && parsed >= 0 {
+			offset = parsed
+		}
+	}
+	return
+}
+
+// ValidateCreateFilamentRequest validates a CreateFilamentRequest DTO.
+// Re-exports the service-layer validator for handler use.
+func ValidateCreateFilamentRequest(req dtos.CreateFilamentRequest) error {
+	return services.ValidateCreateFilamentRequest(req)
+}
+
+// ValidateUpdateFilamentRequest validates an UpdateFilamentRequest DTO.
+// Re-exports the service-layer validator for handler use.
+func ValidateUpdateFilamentRequest(req dtos.UpdateFilamentRequest) error {
+	return services.ValidateUpdateFilamentRequest(req)
+}

backend/internal/handlers/material_finish_handler.go

@@ -0,0 +1,34 @@
+package handlers
+
+import (
+	"log/slog"
+	"net/http"
+
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/dtos"
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/repositories"
+)
+
+// MaterialFinishHandler handles requests for material finish lookup data.
+type MaterialFinishHandler struct {
+	repo *repositories.MaterialFinishRepository
+}
+
+// NewMaterialFinishHandler creates a MaterialFinishHandler with the given repository.
+func NewMaterialFinishHandler(repo *repositories.MaterialFinishRepository) *MaterialFinishHandler {
+	return &MaterialFinishHandler{repo: repo}
+}
+
+// List handles GET /api/finishes — returns all material finishes.
+func (h *MaterialFinishHandler) List(w http.ResponseWriter, r *http.Request) {
+	finishes, err := h.repo.GetAll(r.Context())
+	if err != nil {
+		slog.Error("failed to list finishes", "error", err)
+		writeJSON(w, http.StatusInternalServerError, dtos.ErrorResponse{
+			Error: "internal server error",
+			Code:  http.StatusInternalServerError,
+		})
+		return
+	}
+
+	writeJSON(w, http.StatusOK, dtos.SingleResponse{Data: finishes})
+}

backend/internal/handlers/material_handler.go

@@ -0,0 +1,34 @@
+package handlers
+
+import (
+	"log/slog"
+	"net/http"
+
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/dtos"
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/repositories"
+)
+
+// MaterialHandler handles requests for material lookup data.
+type MaterialHandler struct {
+	repo *repositories.MaterialRepository
+}
+
+// NewMaterialHandler creates a MaterialHandler with the given repository.
+func NewMaterialHandler(repo *repositories.MaterialRepository) *MaterialHandler {
+	return &MaterialHandler{repo: repo}
+}
+
+// List handles GET /api/materials — returns all material bases.
+func (h *MaterialHandler) List(w http.ResponseWriter, r *http.Request) {
+	materials, err := h.repo.GetAll(r.Context())
+	if err != nil {
+		slog.Error("failed to list materials", "error", err)
+		writeJSON(w, http.StatusInternalServerError, dtos.ErrorResponse{
+			Error: "internal server error",
+			Code:  http.StatusInternalServerError,
+		})
+		return
+	}
+
+	writeJSON(w, http.StatusOK, dtos.SingleResponse{Data: materials})
+}

backend/internal/handlers/material_modifier_handler.go

@@ -0,0 +1,34 @@
+package handlers
+
+import (
+	"log/slog"
+	"net/http"
+
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/dtos"
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/repositories"
+)
+
+// MaterialModifierHandler handles requests for material modifier lookup data.
+type MaterialModifierHandler struct {
+	repo *repositories.MaterialModifierRepository
+}
+
+// NewMaterialModifierHandler creates a MaterialModifierHandler with the given repository.
+func NewMaterialModifierHandler(repo *repositories.MaterialModifierRepository) *MaterialModifierHandler {
+	return &MaterialModifierHandler{repo: repo}
+}
+
+// List handles GET /api/modifiers — returns all material modifiers.
+func (h *MaterialModifierHandler) List(w http.ResponseWriter, r *http.Request) {
+	modifiers, err := h.repo.GetAll(r.Context())
+	if err != nil {
+		slog.Error("failed to list modifiers", "error", err)
+		writeJSON(w, http.StatusInternalServerError, dtos.ErrorResponse{
+			Error: "internal server error",
+			Code:  http.StatusInternalServerError,
+		})
+		return
+	}
+
+	writeJSON(w, http.StatusOK, dtos.SingleResponse{Data: modifiers})
+}

backend/internal/handlers/print_job_handler.go

@@ -0,0 +1,60 @@
+package handlers
+
+import (
+	"log/slog"
+	"net/http"
+	"strconv"
+
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/dtos"
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/repositories"
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/services"
+)
+
+// PrintJobHandler handles HTTP requests for print job operations.
+type PrintJobHandler struct {
+	service *services.PrintJobService
+}
+
+// NewPrintJobHandler creates a PrintJobHandler with the given service.
+func NewPrintJobHandler(service *services.PrintJobService) *PrintJobHandler {
+	return &PrintJobHandler{service: service}
+}
+
+// List handles GET /api/print-jobs — returns paginated, filtered print jobs.
+func (h *PrintJobHandler) List(w http.ResponseWriter, r *http.Request) {
+	limit, offset := parsePagination(r)
+	filter := repositories.PrintJobFilter{
+		Status: r.URL.Query().Get("status"),
+		Limit:  limit,
+		Offset: offset,
+	}
+
+	if pidStr := r.URL.Query().Get("printer_id"); pidStr != "" {
+		pid, err := strconv.Atoi(pidStr)
+		if err != nil {
+			writeJSON(w, http.StatusBadRequest, dtos.ErrorResponse{
+				Error: "invalid printer_id",
+				Code:  http.StatusBadRequest,
+			})
+			return
+		}
+		filter.PrinterID = &pid
+	}
+
+	jobs, total, err := h.service.List(r.Context(), filter)
+	if err != nil {
+		slog.Error("failed to list print jobs", "error", err)
+		writeJSON(w, http.StatusInternalServerError, dtos.ErrorResponse{
+			Error: "internal server error",
+			Code:  http.StatusInternalServerError,
+		})
+		return
+	}
+
+	writeJSON(w, http.StatusOK, dtos.ListResponse{
+		Data:   jobs,
+		Total:  total,
+		Limit:  limit,
+		Offset: offset,
+	})
+}

backend/internal/handlers/printer_handler.go

@@ -0,0 +1,34 @@
+package handlers
+
+import (
+	"log/slog"
+	"net/http"
+
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/dtos"
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/services"
+)
+
+// PrinterHandler handles HTTP requests for printer listings.
+type PrinterHandler struct {
+	service *services.PrinterService
+}
+
+// NewPrinterHandler creates a PrinterHandler with the given service.
+func NewPrinterHandler(service *services.PrinterService) *PrinterHandler {
+	return &PrinterHandler{service: service}
+}
+
+// List handles GET /api/printers — returns all printers with printer_type info.
+func (h *PrinterHandler) List(w http.ResponseWriter, r *http.Request) {
+	printers, err := h.service.List(r.Context())
+	if err != nil {
+		slog.Error("failed to list printers", "error", err)
+		writeJSON(w, http.StatusInternalServerError, dtos.ErrorResponse{
+			Error: "internal server error",
+			Code:  http.StatusInternalServerError,
+		})
+		return
+	}
+
+	writeJSON(w, http.StatusOK, dtos.SingleResponse{Data: printers})
+}

backend/internal/handlers/usage_log_handler.go

@@ -0,0 +1,70 @@
+package handlers
+
+import (
+	"log/slog"
+	"net/http"
+	"strconv"
+
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/dtos"
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/repositories"
+)
+
+// UsageLogHandler handles HTTP requests for usage log operations.
+type UsageLogHandler struct {
+	repo *repositories.UsageLogRepository
+}
+
+// NewUsageLogHandler creates a UsageLogHandler with the given repository.
+func NewUsageLogHandler(repo *repositories.UsageLogRepository) *UsageLogHandler {
+	return &UsageLogHandler{repo: repo}
+}
+
+// List handles GET /api/usage-logs — returns paginated, filtered usage logs.
+func (h *UsageLogHandler) List(w http.ResponseWriter, r *http.Request) {
+	limit, offset := parsePagination(r)
+	filter := repositories.UsageLogFilter{
+		Limit:  limit,
+		Offset: offset,
+	}
+
+	if sidStr := r.URL.Query().Get("spool_id"); sidStr != "" {
+		sid, err := strconv.Atoi(sidStr)
+		if err != nil {
+			writeJSON(w, http.StatusBadRequest, dtos.ErrorResponse{
+				Error: "invalid spool_id",
+				Code:  http.StatusBadRequest,
+			})
+			return
+		}
+		filter.SpoolID = &sid
+	}
+
+	if jidStr := r.URL.Query().Get("job_id"); jidStr != "" {
+		jid, err := strconv.Atoi(jidStr)
+		if err != nil {
+			writeJSON(w, http.StatusBadRequest, dtos.ErrorResponse{
+				Error: "invalid job_id",
+				Code:  http.StatusBadRequest,
+			})
+			return
+		}
+		filter.JobID = &jid
+	}
+
+	logs, total, err := h.repo.GetAll(r.Context(), filter)
+	if err != nil {
+		slog.Error("failed to list usage logs", "error", err)
+		writeJSON(w, http.StatusInternalServerError, dtos.ErrorResponse{
+			Error: "internal server error",
+			Code:  http.StatusInternalServerError,
+		})
+		return
+	}
+
+	writeJSON(w, http.StatusOK, dtos.ListResponse{
+		Data:   logs,
+		Total:  total,
+		Limit:  limit,
+		Offset: offset,
+	})
+}

backend/internal/models/models.go

@@ -0,0 +1,162 @@
+// Package models defines the Extrudex domain model structs.
+// These map 1:1 to PostgreSQL tables with snake_case JSON serialization.
+// Nullable fields use pointer types; all timestamps are time.Time.
+package models
+
+import "time"
+
+// ============================================================================
+// Lookup Tables
+// ============================================================================
+
+// PrinterType represents a printer technology category (fdm, resin, etc.).
+type PrinterType struct {
+	ID        int       `json:"id"`
+	Name      string    `json:"name"`
+	CreatedAt time.Time `json:"created_at"`
+	UpdatedAt time.Time `json:"updated_at"`
+}
+
+// JobStatus represents a print job lifecycle state.
+type JobStatus struct {
+	ID        int       `json:"id"`
+	Name      string    `json:"name"`
+	CreatedAt time.Time `json:"created_at"`
+	UpdatedAt time.Time `json:"updated_at"`
+}
+
+// MaterialBase represents a base material type (PLA, PETG, ABS, etc.).
+// Density and temperature ranges are stored here for grams-calculation and slicing guidance.
+type MaterialBase struct {
+	ID               int        `json:"id"`
+	Name             string     `json:"name"`
+	DensityGCm3      float64    `json:"density_g_cm3"`
+	ExtrusionTempMin *int       `json:"extrusion_temp_min,omitempty"`
+	ExtrusionTempMax *int       `json:"extrusion_temp_max,omitempty"`
+	BedTempMin       *int       `json:"bed_temp_min,omitempty"`
+	BedTempMax       *int       `json:"bed_temp_max,omitempty"`
+	CreatedAt        time.Time  `json:"created_at"`
+	UpdatedAt        time.Time  `json:"updated_at"`
+}
+
+// MaterialFinish represents the visual/texture finish (Basic, Silk, Matte, etc.).
+type MaterialFinish struct {
+	ID          int       `json:"id"`
+	Name        string    `json:"name"`
+	Description *string   `json:"description,omitempty"`
+	CreatedAt   time.Time `json:"created_at"`
+	UpdatedAt   time.Time `json:"updated_at"`
+}
+
+// MaterialModifier represents an additive property (Carbon Fiber, Wood-Filled, etc.).
+type MaterialModifier struct {
+	ID          int       `json:"id"`
+	Name        string    `json:"name"`
+	Description *string   `json:"description,omitempty"`
+	CreatedAt   time.Time `json:"created_at"`
+	UpdatedAt   time.Time `json:"updated_at"`
+}
+
+// ============================================================================
+// Core Entity Tables
+// ============================================================================
+
+// Printer represents a 3D printer in the fleet.
+type Printer struct {
+	ID              int        `json:"id"`
+	Name            string     `json:"name"`
+	PrinterTypeID   int        `json:"printer_type_id"`
+	PrinterType     *PrinterType `json:"printer_type,omitempty"` // populated on JOIN queries
+	Manufacturer    *string    `json:"manufacturer,omitempty"`
+	Model           *string    `json:"model,omitempty"`
+	MoonrakerURL    *string    `json:"moonraker_url,omitempty"`
+	MoonrakerAPIKey *string    `json:"moonraker_api_key,omitempty"`
+	MQTTBrokerHost  *string    `json:"mqtt_broker_host,omitempty"`
+	MQTTTopicPrefix *string    `json:"mqtt_topic_prefix,omitempty"`
+	MQTTTLSEnabled  bool       `json:"mqtt_tls_enabled"`
+	IsActive        bool       `json:"is_active"`
+	CreatedAt       time.Time  `json:"created_at"`
+	UpdatedAt       time.Time  `json:"updated_at"`
+}
+
+// FilamentSpool represents a physical filament spool in inventory.
+// material_finish_id defaults to 1 ("Basic"); material_modifier_id is optional.
+// Grams are always physically measured values — grams_used is derived, not stored.
+type FilamentSpool struct {
+	ID                    int             `json:"id"`
+	Name                  string          `json:"name"`
+	MaterialBaseID        int             `json:"material_base_id"`
+	MaterialBase          *MaterialBase   `json:"material_base,omitempty"`   // JOIN
+	MaterialFinishID      int             `json:"material_finish_id"`
+	MaterialFinish        *MaterialFinish `json:"material_finish,omitempty"` // JOIN
+	MaterialModifierID    *int            `json:"material_modifier_id,omitempty"`
+	MaterialModifier      *MaterialModifier `json:"material_modifier,omitempty"` // JOIN
+	ColorHex              string          `json:"color_hex"`
+	Brand                 *string         `json:"brand,omitempty"`
+	DiameterMM            float64         `json:"diameter_mm"`
+	InitialGrams          int             `json:"initial_grams"`
+	RemainingGrams        int             `json:"remaining_grams"`
+	SpoolWeightGrams      *int            `json:"spool_weight_grams,omitempty"`
+	CostUSD               *float64        `json:"cost_usd,omitempty"`
+	LowStockThresholdGrams int            `json:"low_stock_threshold_grams"`
+	Notes                 *string         `json:"notes,omitempty"`
+	Barcode               *string         `json:"barcode,omitempty"`
+	DeletedAt             *time.Time      `json:"deleted_at,omitempty"`
+	CreatedAt             time.Time       `json:"created_at"`
+	UpdatedAt             time.Time       `json:"updated_at"`
+}
+
+// PrintJob represents a single print on a specific printer.
+// The filament_spool_id is a convenience reference; multi-spool jobs track usage in usage_logs.
+type PrintJob struct {
+	ID                      int         `json:"id"`
+	PrinterID               int         `json:"printer_id"`
+	Printer                 *Printer    `json:"printer,omitempty"`      // JOIN
+	FilamentSpoolID         *int        `json:"filament_spool_id,omitempty"`
+	FilamentSpool           *FilamentSpool `json:"filament_spool,omitempty"` // JOIN
+	JobName                 string      `json:"job_name"`
+	FileName                *string     `json:"file_name,omitempty"`
+	JobStatusID             int         `json:"job_status_id"`
+	JobStatus               *JobStatus  `json:"job_status,omitempty"`  // JOIN
+	StartedAt               *time.Time  `json:"started_at,omitempty"`
+	CompletedAt             *time.Time  `json:"completed_at,omitempty"`
+	DurationSeconds         *int        `json:"duration_seconds,omitempty"`
+	EstimatedDurationSeconds *int       `json:"estimated_duration_seconds,omitempty"`
+	TotalMMExtruded         *float64    `json:"total_mm_extruded,omitempty"`
+	TotalGramsUsed          *float64    `json:"total_grams_used,omitempty"`
+	TotalCostUSD            *float64    `json:"total_cost_usd,omitempty"`
+	Notes                   *string     `json:"notes,omitempty"`
+	DeletedAt               *time.Time  `json:"deleted_at,omitempty"`
+	CreatedAt               time.Time   `json:"created_at"`
+	UpdatedAt               time.Time   `json:"updated_at"`
+}
+
+// UsageLog records filament consumption for a specific spool during a print job.
+// This is the atomic unit of filament tracking — grams are derived from mm_extruded.
+type UsageLog struct {
+	ID              int            `json:"id"`
+	PrintJobID      int            `json:"print_job_id"`
+	PrintJob        *PrintJob      `json:"print_job,omitempty"`        // JOIN
+	FilamentSpoolID int            `json:"filament_spool_id"`
+	FilamentSpool   *FilamentSpool `json:"filament_spool,omitempty"`   // JOIN
+	MMExtruded      float64        `json:"mm_extruded"`
+	GramsUsed       float64        `json:"grams_used"`
+	CostUSD         *float64       `json:"cost_usd,omitempty"`
+	LoggedAt        time.Time      `json:"logged_at"`
+	CreatedAt       time.Time      `json:"created_at"`
+}
+
+// ============================================================================
+// Application Settings
+// ============================================================================
+
+// Setting represents a key-value application configuration entry.
+// The value is stored as JSONB in PostgreSQL, allowing flexible typed config.
+type Setting struct {
+	ID          int       `json:"id"`
+	Key         string    `json:"key"`
+	Value       []byte    `json:"value"`  // raw JSON — marshalled/unmarshalled by caller
+	Description *string   `json:"description,omitempty"`
+	CreatedAt   time.Time `json:"created_at"`
+	UpdatedAt   time.Time `json:"updated_at"`
+}

backend/internal/repositories/filament_repository.go

@@ -0,0 +1,285 @@
+package repositories
+
+import (
+	"context"
+	"fmt"
+	"strings"
+	"time"
+
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/models"
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+// FilamentRepository handles database queries for filament_spools.
+type FilamentRepository struct {
+	pool *pgxpool.Pool
+}
+
+// NewFilamentRepository creates a FilamentRepository backed by the given pool.
+func NewFilamentRepository(pool *pgxpool.Pool) *FilamentRepository {
+	return &FilamentRepository{pool: pool}
+}
+
+// FilamentFilter holds query parameters for listing filament spools.
+type FilamentFilter struct {
+	Material string // filter by material_base name (case-insensitive)
+	Finish   string // filter by material_finish name (case-insensitive)
+	Color    string // filter by exact color_hex match
+	LowStock bool   // if true, filter for remaining_grams <= low_stock_threshold_grams
+	Limit    int
+	Offset   int
+}
+
+// spoolScanFields is the common SELECT column list for filament spools with JOINs.
+const spoolScanFields = `
+	s.id, s.name,
+	s.material_base_id,
+	COALESCE(mb.name, '') as material_base_name,
+	COALESCE(mb.density_g_cm3, 0) as material_base_density_g_cm3,
+	COALESCE(mb.extrusion_temp_min, NULL::int) as material_base_extrusion_temp_min,
+	COALESCE(mb.extrusion_temp_max, NULL::int) as material_base_extrusion_temp_max,
+	COALESCE(mb.bed_temp_min, NULL::int) as material_base_bed_temp_min,
+	COALESCE(mb.bed_temp_max, NULL::int) as material_base_bed_temp_max,
+	COALESCE(mb.created_at, s.created_at) as material_base_created_at,
+	COALESCE(mb.updated_at, s.created_at) as material_base_updated_at,
+	s.material_finish_id,
+	COALESCE(mf.name, '') as material_finish_name,
+	mf.description as material_finish_description,
+	COALESCE(mf.created_at, s.created_at) as material_finish_created_at,
+	COALESCE(mf.updated_at, s.created_at) as material_finish_updated_at,
+	s.material_modifier_id,
+	mm.name as material_modifier_name,
+	mm.description as material_modifier_description,
+	mm.created_at as material_modifier_created_at,
+	mm.updated_at as material_modifier_updated_at,
+	s.color_hex, s.brand, s.diameter_mm,
+	s.initial_grams, s.remaining_grams, s.spool_weight_grams,
+	s.cost_usd, s.low_stock_threshold_grams,
+	s.notes, s.barcode,
+	s.deleted_at, s.created_at, s.updated_at`
+
+const spoolFromJoins = `
+	FROM filament_spools s
+	LEFT JOIN material_bases mb ON s.material_base_id = mb.id
+	LEFT JOIN material_finishes mf ON s.material_finish_id = mf.id
+	LEFT JOIN material_modifiers mm ON s.material_modifier_id = mm.id`
+
+// scanSpoolWithJoins scans a full spool row including all JOINed tables.
+func scanSpoolWithJoins(row interface{ Scan(...interface{}) error }) (models.FilamentSpool, error) {
+	var s models.FilamentSpool
+	var mb models.MaterialBase
+	var mf models.MaterialFinish
+	var mfDesc *string
+	var modifierID *int
+	var modName, modDesc *string
+	var modCreatedAt, modUpdatedAt *time.Time
+
+	err := row.Scan(
+		&s.ID, &s.Name,
+		&s.MaterialBaseID,
+		&mb.Name, &mb.DensityGCm3,
+		&mb.ExtrusionTempMin, &mb.ExtrusionTempMax,
+		&mb.BedTempMin, &mb.BedTempMax,
+		&mb.CreatedAt, &mb.UpdatedAt,
+		&s.MaterialFinishID,
+		&mf.Name, &mfDesc,
+		&mf.CreatedAt, &mf.UpdatedAt,
+		&modifierID,
+		&modName, &modDesc,
+		&modCreatedAt, &modUpdatedAt,
+		&s.ColorHex, &s.Brand, &s.DiameterMM,
+		&s.InitialGrams, &s.RemainingGrams, &s.SpoolWeightGrams,
+		&s.CostUSD, &s.LowStockThresholdGrams,
+		&s.Notes, &s.Barcode,
+		&s.DeletedAt, &s.CreatedAt, &s.UpdatedAt,
+	)
+	if err != nil {
+		return s, err
+	}
+
+	mb.ID = s.MaterialBaseID
+	s.MaterialBase = &mb
+
+	mf.ID = s.MaterialFinishID
+	if mfDesc != nil {
+		mf.Description = mfDesc
+	}
+	s.MaterialFinish = &mf
+
+	s.MaterialModifierID = modifierID
+	if modifierID != nil && modName != nil {
+		mm := models.MaterialModifier{
+			ID:   *modifierID,
+			Name: *modName,
+		}
+		if modDesc != nil {
+			mm.Description = modDesc
+		}
+		if modCreatedAt != nil {
+			mm.CreatedAt = *modCreatedAt
+		}
+		if modUpdatedAt != nil {
+			mm.UpdatedAt = *modUpdatedAt
+		}
+		s.MaterialModifier = &mm
+	}
+
+	return s, nil
+}
+
+// GetAll returns filament spools matching the given filters, with pagination.
+// Returns results, total matching count, and any error.
+func (r *FilamentRepository) GetAll(ctx context.Context, filter FilamentFilter) ([]models.FilamentSpool, int, error) {
+	conditions := []string{"s.deleted_at IS NULL"}
+	args := []interface{}{}
+	argIdx := 1
+
+	if filter.Material != "" {
+		conditions = append(conditions, fmt.Sprintf("LOWER(mb.name) = LOWER($%d)", argIdx))
+		args = append(args, filter.Material)
+		argIdx++
+	}
+	if filter.Finish != "" {
+		conditions = append(conditions, fmt.Sprintf("LOWER(mf.name) = LOWER($%d)", argIdx))
+		args = append(args, filter.Finish)
+		argIdx++
+	}
+	if filter.Color != "" {
+		conditions = append(conditions, fmt.Sprintf("s.color_hex = $%d", argIdx))
+		args = append(args, filter.Color)
+		argIdx++
+	}
+	if filter.LowStock {
+		conditions = append(conditions, "s.remaining_grams <= s.low_stock_threshold_grams")
+	}
+
+	whereClause := ""
+	if len(conditions) > 0 {
+		whereClause = "WHERE " + strings.Join(conditions, " AND ")
+	}
+
+	// Count total.
+	var total int
+	countQuery := "SELECT COUNT(*) " + spoolFromJoins + " " + whereClause
+	if err := r.pool.QueryRow(ctx, countQuery, args...).Scan(&total); err != nil {
+		return nil, 0, err
+	}
+
+	// Query with pagination.
+	dataQuery := "SELECT " + spoolScanFields + " " + spoolFromJoins + " " +
+		whereClause +
+		" ORDER BY s.name ASC" +
+		fmt.Sprintf(" LIMIT $%d OFFSET $%d", argIdx, argIdx+1)
+
+	dataArgs := make([]interface{}, len(args))
+	copy(dataArgs, args)
+	dataArgs = append(dataArgs, filter.Limit, filter.Offset)
+
+	rows, err := r.pool.Query(ctx, dataQuery, dataArgs...)
+	if err != nil {
+		return nil, 0, err
+	}
+	defer rows.Close()
+
+	var spools []models.FilamentSpool
+	for rows.Next() {
+		s, err := scanSpoolWithJoins(rows)
+		if err != nil {
+			return nil, 0, err
+		}
+		spools = append(spools, s)
+	}
+	if err := rows.Err(); err != nil {
+		return nil, 0, err
+	}
+	if spools == nil {
+		spools = []models.FilamentSpool{}
+	}
+
+	return spools, total, nil
+}
+
+// GetByID returns a single filament spool by ID with JOINed data.
+// Returns nil if not found or soft-deleted.
+func (r *FilamentRepository) GetByID(ctx context.Context, id int) (*models.FilamentSpool, error) {
+	query := "SELECT " + spoolScanFields + " " + spoolFromJoins +
+		" WHERE s.id = $1 AND s.deleted_at IS NULL"
+
+	row := r.pool.QueryRow(ctx, query, id)
+	s, err := scanSpoolWithJoins(row)
+	if err != nil {
+		return nil, err
+	}
+	return &s, nil
+}
+
+// Create inserts a new filament spool and returns the created spool with JOINed data.
+func (r *FilamentRepository) Create(ctx context.Context, spool *models.FilamentSpool) (*models.FilamentSpool, error) {
+	var id int
+	err := r.pool.QueryRow(ctx, `
+		INSERT INTO filament_spools (
+			name, material_base_id, material_finish_id, material_modifier_id,
+			color_hex, brand, diameter_mm, initial_grams, remaining_grams,
+			spool_weight_grams, cost_usd, low_stock_threshold_grams,
+			notes, barcode
+		) VALUES ($1,$2,$3,$4,$5,$6,$7,$8,$9,$10,$11,$12,$13,$14)
+		RETURNING id
+	`,
+		spool.Name, spool.MaterialBaseID, spool.MaterialFinishID, spool.MaterialModifierID,
+		spool.ColorHex, spool.Brand, spool.DiameterMM, spool.InitialGrams, spool.RemainingGrams,
+		spool.SpoolWeightGrams, spool.CostUSD, spool.LowStockThresholdGrams,
+		spool.Notes, spool.Barcode,
+	).Scan(&id)
+	if err != nil {
+		return nil, err
+	}
+
+	return r.GetByID(ctx, id)
+}
+
+// Update applies partial updates to an existing filament spool.
+// Only non-nil fields in the update map are applied.
+// Returns the updated spool.
+func (r *FilamentRepository) Update(ctx context.Context, id int, updates map[string]interface{}) (*models.FilamentSpool, error) {
+	if len(updates) == 0 {
+		return r.GetByID(ctx, id)
+	}
+
+	setClauses := []string{"updated_at = NOW()"}
+	args := []interface{}{}
+	argIdx := 1
+
+	for col, val := range updates {
+		setClauses = append(setClauses, fmt.Sprintf("%s = $%d", col, argIdx))
+		args = append(args, val)
+		argIdx++
+	}
+
+	args = append(args, id)
+	query := fmt.Sprintf("UPDATE filament_spools SET %s WHERE id = $%d AND deleted_at IS NULL",
+		strings.Join(setClauses, ", "), argIdx)
+
+	result, err := r.pool.Exec(ctx, query, args...)
+	if err != nil {
+		return nil, err
+	}
+	if result.RowsAffected() == 0 {
+		return nil, nil // not found or deleted
+	}
+
+	return r.GetByID(ctx, id)
+}
+
+// SoftDelete marks a filament spool as deleted by setting deleted_at = NOW().
+// Returns true if a row was affected.
+func (r *FilamentRepository) SoftDelete(ctx context.Context, id int) (bool, error) {
+	result, err := r.pool.Exec(ctx, `
+		UPDATE filament_spools
+		SET deleted_at = NOW(), updated_at = NOW()
+		WHERE id = $1 AND deleted_at IS NULL
+	`, id)
+	if err != nil {
+		return false, err
+	}
+	return result.RowsAffected() > 0, nil
+}

backend/internal/repositories/material_finish_repository.go

@@ -0,0 +1,50 @@
+package repositories
+
+import (
+	"context"
+
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/models"
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+// MaterialFinishRepository handles database queries for material finishes.
+type MaterialFinishRepository struct {
+	pool *pgxpool.Pool
+}
+
+// NewMaterialFinishRepository creates a MaterialFinishRepository backed by the given pool.
+func NewMaterialFinishRepository(pool *pgxpool.Pool) *MaterialFinishRepository {
+	return &MaterialFinishRepository{pool: pool}
+}
+
+// GetAll returns all material finishes ordered by name.
+func (r *MaterialFinishRepository) GetAll(ctx context.Context) ([]models.MaterialFinish, error) {
+	rows, err := r.pool.Query(ctx, `
+		SELECT id, name, description, created_at, updated_at
+		FROM material_finishes
+		ORDER BY name
+	`)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var finishes []models.MaterialFinish
+	for rows.Next() {
+		var f models.MaterialFinish
+		if err := rows.Scan(
+			&f.ID, &f.Name, &f.Description,
+			&f.CreatedAt, &f.UpdatedAt,
+		); err != nil {
+			return nil, err
+		}
+		finishes = append(finishes, f)
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+	if finishes == nil {
+		finishes = []models.MaterialFinish{}
+	}
+	return finishes, nil
+}

backend/internal/repositories/material_modifier_repository.go

@@ -0,0 +1,50 @@
+package repositories
+
+import (
+	"context"
+
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/models"
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+// MaterialModifierRepository handles database queries for material modifiers.
+type MaterialModifierRepository struct {
+	pool *pgxpool.Pool
+}
+
+// NewMaterialModifierRepository creates a MaterialModifierRepository backed by the given pool.
+func NewMaterialModifierRepository(pool *pgxpool.Pool) *MaterialModifierRepository {
+	return &MaterialModifierRepository{pool: pool}
+}
+
+// GetAll returns all material modifiers ordered by name.
+func (r *MaterialModifierRepository) GetAll(ctx context.Context) ([]models.MaterialModifier, error) {
+	rows, err := r.pool.Query(ctx, `
+		SELECT id, name, description, created_at, updated_at
+		FROM material_modifiers
+		ORDER BY name
+	`)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var modifiers []models.MaterialModifier
+	for rows.Next() {
+		var m models.MaterialModifier
+		if err := rows.Scan(
+			&m.ID, &m.Name, &m.Description,
+			&m.CreatedAt, &m.UpdatedAt,
+		); err != nil {
+			return nil, err
+		}
+		modifiers = append(modifiers, m)
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+	if modifiers == nil {
+		modifiers = []models.MaterialModifier{}
+	}
+	return modifiers, nil
+}

backend/internal/repositories/material_repository.go

@@ -0,0 +1,54 @@
+// Package repositories provides data access logic backed by PostgreSQL via pgxpool.
+package repositories
+
+import (
+	"context"
+
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/models"
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+// MaterialRepository handles database queries for material lookup tables.
+type MaterialRepository struct {
+	pool *pgxpool.Pool
+}
+
+// NewMaterialRepository creates a MaterialRepository backed by the given pool.
+func NewMaterialRepository(pool *pgxpool.Pool) *MaterialRepository {
+	return &MaterialRepository{pool: pool}
+}
+
+// GetAll returns all material bases ordered by name.
+func (r *MaterialRepository) GetAll(ctx context.Context) ([]models.MaterialBase, error) {
+	rows, err := r.pool.Query(ctx, `
+		SELECT id, name, density_g_cm3, extrusion_temp_min, extrusion_temp_max,
+		       bed_temp_min, bed_temp_max, created_at, updated_at
+		FROM material_bases
+		ORDER BY name
+	`)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var materials []models.MaterialBase
+	for rows.Next() {
+		var m models.MaterialBase
+		if err := rows.Scan(
+			&m.ID, &m.Name, &m.DensityGCm3,
+			&m.ExtrusionTempMin, &m.ExtrusionTempMax,
+			&m.BedTempMin, &m.BedTempMax,
+			&m.CreatedAt, &m.UpdatedAt,
+		); err != nil {
+			return nil, err
+		}
+		materials = append(materials, m)
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+	if materials == nil {
+		materials = []models.MaterialBase{}
+	}
+	return materials, nil
+}

backend/internal/repositories/print_job_repository.go

@@ -0,0 +1,157 @@
+package repositories
+
+import (
+	"context"
+	"fmt"
+	"strings"
+
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/models"
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+// PrintJobRepository handles database queries for print_jobs.
+type PrintJobRepository struct {
+	pool *pgxpool.Pool
+}
+
+// NewPrintJobRepository creates a PrintJobRepository backed by the given pool.
+func NewPrintJobRepository(pool *pgxpool.Pool) *PrintJobRepository {
+	return &PrintJobRepository{pool: pool}
+}
+
+// PrintJobFilter holds query parameters for listing print jobs.
+type PrintJobFilter struct {
+	Status    string // filter by job_status name (case-insensitive)
+	PrinterID *int   // filter by printer_id
+	Limit     int
+	Offset    int
+}
+
+// scanPrintJobWithJoins scans a print_job row with JOINed tables.
+func (r *PrintJobRepository) scanPrintJobWithJoins(row interface{ Scan(...interface{}) error }) (models.PrintJob, error) {
+	var pj models.PrintJob
+	var js models.JobStatus
+
+	err := row.Scan(
+		&pj.ID, &pj.PrinterID, &pj.FilamentSpoolID,
+		&pj.JobName, &pj.FileName,
+		&pj.JobStatusID,
+		&pj.StartedAt, &pj.CompletedAt,
+		&pj.DurationSeconds, &pj.EstimatedDurationSeconds,
+		&pj.TotalMMExtruded, &pj.TotalGramsUsed, &pj.TotalCostUSD,
+		&pj.Notes,
+		&pj.DeletedAt, &pj.CreatedAt, &pj.UpdatedAt,
+		&js.ID, &js.Name,
+		&js.CreatedAt, &js.UpdatedAt,
+	)
+	if err != nil {
+		return pj, err
+	}
+
+	pj.JobStatus = &js
+	return pj, nil
+}
+
+// GetAll returns print jobs matching the given filters, with pagination.
+func (r *PrintJobRepository) GetAll(ctx context.Context, filter PrintJobFilter) ([]models.PrintJob, int, error) {
+	conditions := []string{"pj.deleted_at IS NULL"}
+	args := []interface{}{}
+	argIdx := 1
+
+	if filter.Status != "" {
+		conditions = append(conditions, fmt.Sprintf("LOWER(js.name) = LOWER($%d)", argIdx))
+		args = append(args, filter.Status)
+		argIdx++
+	}
+	if filter.PrinterID != nil {
+		conditions = append(conditions, fmt.Sprintf("pj.printer_id = $%d", argIdx))
+		args = append(args, *filter.PrinterID)
+		argIdx++
+	}
+
+	whereClause := ""
+	if len(conditions) > 0 {
+		whereClause = "WHERE " + strings.Join(conditions, " AND ")
+	}
+
+	// Count.
+	var total int
+	countQuery := `SELECT COUNT(*)
+		FROM print_jobs pj
+		LEFT JOIN job_statuses js ON pj.job_status_id = js.id
+	` + " " + whereClause
+	if err := r.pool.QueryRow(ctx, countQuery, args...).Scan(&total); err != nil {
+		return nil, 0, err
+	}
+
+	// Query with pagination.
+	dataQuery := `SELECT
+		pj.id, pj.printer_id, pj.filament_spool_id,
+		pj.job_name, pj.file_name,
+		pj.job_status_id,
+		pj.started_at, pj.completed_at,
+		pj.duration_seconds, pj.estimated_duration_seconds,
+		pj.total_mm_extruded, pj.total_grams_used, pj.total_cost_usd,
+		pj.notes,
+		pj.deleted_at, pj.created_at, pj.updated_at,
+		js.id, js.name,
+		js.created_at, js.updated_at
+	FROM print_jobs pj
+	LEFT JOIN job_statuses js ON pj.job_status_id = js.id
+	` + whereClause +
+		" ORDER BY pj.created_at DESC" +
+		fmt.Sprintf(" LIMIT $%d OFFSET $%d", argIdx, argIdx+1)
+
+	dataArgs := make([]interface{}, len(args))
+	copy(dataArgs, args)
+	dataArgs = append(dataArgs, filter.Limit, filter.Offset)
+
+	rows, err := r.pool.Query(ctx, dataQuery, dataArgs...)
+	if err != nil {
+		return nil, 0, err
+	}
+	defer rows.Close()
+
+	var jobs []models.PrintJob
+	for rows.Next() {
+		pj, err := r.scanPrintJobWithJoins(rows)
+		if err != nil {
+			return nil, 0, err
+		}
+		jobs = append(jobs, pj)
+	}
+	if err := rows.Err(); err != nil {
+		return nil, 0, err
+	}
+	if jobs == nil {
+		jobs = []models.PrintJob{}
+	}
+
+	return jobs, total, nil
+}
+
+// GetByID returns a single print job by ID with JOINed job_status.
+func (r *PrintJobRepository) GetByID(ctx context.Context, id int) (*models.PrintJob, error) {
+	row := r.pool.QueryRow(ctx, `
+		SELECT
+			pj.id, pj.printer_id, pj.filament_spool_id,
+			pj.job_name, pj.file_name,
+			pj.job_status_id,
+			pj.started_at, pj.completed_at,
+			pj.duration_seconds, pj.estimated_duration_seconds,
+			pj.total_mm_extruded, pj.total_grams_used, pj.total_cost_usd,
+			pj.notes,
+			pj.deleted_at, pj.created_at, pj.updated_at,
+			js.id, js.name,
+			js.created_at, js.updated_at
+		FROM print_jobs pj
+		LEFT JOIN job_statuses js ON pj.job_status_id = js.id
+		WHERE pj.id = $1 AND pj.deleted_at IS NULL
+	`, id)
+
+	pj, err := r.scanPrintJobWithJoins(row)
+	if err != nil {
+		return nil, err
+	}
+	return &pj, nil
+}

backend/internal/repositories/printer_repository.go

@@ -0,0 +1,78 @@
+package repositories
+
+import (
+	"context"
+
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/models"
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+// PrinterRepository handles database queries for printers.
+type PrinterRepository struct {
+	pool *pgxpool.Pool
+}
+
+// NewPrinterRepository creates a PrinterRepository backed by the given pool.
+func NewPrinterRepository(pool *pgxpool.Pool) *PrinterRepository {
+	return &PrinterRepository{pool: pool}
+}
+
+// scanPrinterWithType scans a printer row with JOINed printer_type.
+func (r *PrinterRepository) scanPrinterWithType(row interface{ Scan(...interface{}) error }) (models.Printer, error) {
+	var p models.Printer
+	var pt models.PrinterType
+
+	err := row.Scan(
+		&p.ID, &p.Name, &p.PrinterTypeID,
+		&p.Manufacturer, &p.Model,
+		&p.MoonrakerURL, &p.MoonrakerAPIKey,
+		&p.MQTTBrokerHost, &p.MQTTTopicPrefix,
+		&p.MQTTTLSEnabled, &p.IsActive,
+		&p.CreatedAt, &p.UpdatedAt,
+		&pt.ID, &pt.Name,
+		&pt.CreatedAt, &pt.UpdatedAt,
+	)
+	if err != nil {
+		return p, err
+	}
+
+	p.PrinterType = &pt
+	return p, nil
+}
+
+// GetAll returns all printers joined with their printer_type, ordered by name.
+func (r *PrinterRepository) GetAll(ctx context.Context) ([]models.Printer, error) {
+	rows, err := r.pool.Query(ctx, `
+		SELECT p.id, p.name, p.printer_type_id,
+		       p.manufacturer, p.model,
+		       p.moonraker_url, p.moonraker_api_key,
+		       p.mqtt_broker_host, p.mqtt_topic_prefix,
+		       p.mqtt_tls_enabled, p.is_active,
+		       p.created_at, p.updated_at,
+		       pt.id, pt.name,
+		       pt.created_at, pt.updated_at
+		FROM printers p
+		JOIN printer_types pt ON p.printer_type_id = pt.id
+		ORDER BY p.name
+	`)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var printers []models.Printer
+	for rows.Next() {
+		p, err := r.scanPrinterWithType(rows)
+		if err != nil {
+			return nil, err
+		}
+		printers = append(printers, p)
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+	if printers == nil {
+		printers = []models.Printer{}
+	}
+	return printers, nil
+}

backend/internal/repositories/usage_log_repository.go

@@ -0,0 +1,96 @@
+package repositories
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/models"
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+// UsageLogRepository handles database queries for usage_logs.
+type UsageLogRepository struct {
+	pool *pgxpool.Pool
+}
+
+// NewUsageLogRepository creates a UsageLogRepository backed by the given pool.
+func NewUsageLogRepository(pool *pgxpool.Pool) *UsageLogRepository {
+	return &UsageLogRepository{pool: pool}
+}
+
+// UsageLogFilter holds query parameters for listing usage logs.
+type UsageLogFilter struct {
+	SpoolID *int // filter by filament_spool_id
+	JobID   *int // filter by print_job_id
+	Limit   int
+	Offset  int
+}
+
+// GetAll returns usage logs matching the given filters, with pagination.
+func (r *UsageLogRepository) GetAll(ctx context.Context, filter UsageLogFilter) ([]models.UsageLog, int, error) {
+	conditions := []string{"1=1"}
+	args := []interface{}{}
+	argIdx := 1
+
+	if filter.SpoolID != nil {
+		conditions = append(conditions, fmt.Sprintf("ul.filament_spool_id = $%d", argIdx))
+		args = append(args, *filter.SpoolID)
+		argIdx++
+	}
+	if filter.JobID != nil {
+		conditions = append(conditions, fmt.Sprintf("ul.print_job_id = $%d", argIdx))
+		args = append(args, *filter.JobID)
+		argIdx++
+	}
+
+	whereClause := "WHERE " + fmt.Sprintf("%s", conditions[0])
+	for _, c := range conditions[1:] {
+		whereClause += " AND " + c
+	}
+
+	// Count.
+	var total int
+	countQuery := "SELECT COUNT(*) FROM usage_logs ul " + whereClause
+	if err := r.pool.QueryRow(ctx, countQuery, args...).Scan(&total); err != nil {
+		return nil, 0, err
+	}
+
+	// Query with pagination.
+	dataQuery := `SELECT id, print_job_id, filament_spool_id, mm_extruded,
+	       grams_used, cost_usd, logged_at, created_at
+	FROM usage_logs ul
+	` + whereClause +
+		" ORDER BY ul.logged_at DESC" +
+		fmt.Sprintf(" LIMIT $%d OFFSET $%d", argIdx, argIdx+1)
+
+	dataArgs := make([]interface{}, len(args))
+	copy(dataArgs, args)
+	dataArgs = append(dataArgs, filter.Limit, filter.Offset)
+
+	rows, err := r.pool.Query(ctx, dataQuery, dataArgs...)
+	if err != nil {
+		return nil, 0, err
+	}
+	defer rows.Close()
+
+	var logs []models.UsageLog
+	for rows.Next() {
+		var l models.UsageLog
+		if err := rows.Scan(
+			&l.ID, &l.PrintJobID, &l.FilamentSpoolID,
+			&l.MMExtruded, &l.GramsUsed, &l.CostUSD,
+			&l.LoggedAt, &l.CreatedAt,
+		); err != nil {
+			return nil, 0, err
+		}
+		logs = append(logs, l)
+	}
+	if err := rows.Err(); err != nil {
+		return nil, 0, err
+	}
+	if logs == nil {
+		logs = []models.UsageLog{}
+	}
+
+	return logs, total, nil
+}

backend/internal/router/router.go

@@ -0,0 +1,96 @@
+package router
+
+import (
+	"net/http"
+	"time"
+
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/config"
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/handlers"
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/repositories"
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/services"
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/sse"
+	"github.com/go-chi/chi/v5"
+	"github.com/go-chi/chi/v5/middleware"
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+// New creates and configures a Chi router with all middleware and handlers mounted.
+func New(cfg *config.Config, dbPool *pgxpool.Pool, sseBC *sse.Broadcaster) chi.Router {
+	r := chi.NewRouter()
+
+	// Middleware
+	r.Use(middleware.RequestID)
+	r.Use(middleware.RealIP)
+	r.Use(middleware.Logger)
+	r.Use(middleware.Recoverer)
+	// Timeout middleware is applied per-route below to exclude SSE
+
+	// CORS
+	r.Use(func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			w.Header().Set("Access-Control-Allow-Origin", cfg.CorsOrigin)
+			w.Header().Set("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS")
+			w.Header().Set("Access-Control-Allow-Headers", "Content-Type, Authorization")
+			if r.Method == http.MethodOptions {
+				w.WriteHeader(http.StatusNoContent)
+				return
+			}
+			next.ServeHTTP(w, r)
+		})
+	})
+
+	// Health check (with timeout)
+	healthHandler := handlers.NewHealthHandler(dbPool)
+	r.With(middleware.Timeout(30 * time.Second)).Get("/health", healthHandler.ServeHTTP)
+
+	// ── Repositories ──────────────────────────────────────────────────────
+	materialRepo := repositories.NewMaterialRepository(dbPool)
+	finishRepo := repositories.NewMaterialFinishRepository(dbPool)
+	modifierRepo := repositories.NewMaterialModifierRepository(dbPool)
+	filamentRepo := repositories.NewFilamentRepository(dbPool)
+	printerRepo := repositories.NewPrinterRepository(dbPool)
+	printJobRepo := repositories.NewPrintJobRepository(dbPool)
+	usageLogRepo := repositories.NewUsageLogRepository(dbPool)
+
+	// ── Services ──────────────────────────────────────────────────────────
+	filamentService := services.NewFilamentService(filamentRepo)
+	printerService := services.NewPrinterService(printerRepo)
+	printJobService := services.NewPrintJobService(printJobRepo)
+
+	// ── Handlers ──────────────────────────────────────────────────────────
+	materialHandler := handlers.NewMaterialHandler(materialRepo)
+	finishHandler := handlers.NewMaterialFinishHandler(finishRepo)
+	modifierHandler := handlers.NewMaterialModifierHandler(modifierRepo)
+	filamentHandler := handlers.NewFilamentHandler(filamentService)
+	printerHandler := handlers.NewPrinterHandler(printerService)
+	printJobHandler := handlers.NewPrintJobHandler(printJobService)
+	usageLogHandler := handlers.NewUsageLogHandler(usageLogRepo)
+
+	// ── API Routes (with timeout) ─────────────────────────────────────────
+	r.Route("/api", func(r chi.Router) {
+		r.Use(middleware.Timeout(60 * time.Second))
+		r.Get("/materials", materialHandler.List)
+		r.Get("/finishes", finishHandler.List)
+		r.Get("/modifiers", modifierHandler.List)
+
+		r.Route("/filaments", func(r chi.Router) {
+			r.Get("/", filamentHandler.List)
+			r.Post("/", filamentHandler.Create)
+			r.Route("/{id}", func(r chi.Router) {
+				r.Get("/", filamentHandler.Get)
+				r.Put("/", filamentHandler.Update)
+				r.Delete("/", filamentHandler.Delete)
+			})
+		})
+
+		r.Get("/printers", printerHandler.List)
+		r.Get("/print-jobs", printJobHandler.List)
+		r.Get("/usage-logs", usageLogHandler.List)
+
+		// SSE Events stream
+		sseHandler := sse.NewHandler(sseBC)
+		r.Get("/events", sseHandler.ServeHTTP)
+	})
+
+	return r
+}

backend/internal/services/services.go

@@ -0,0 +1,82 @@
+// Package services contains business logic and application services.
+package services
+
+import (
+	"context"
+
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/models"
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/repositories"
+)
+
+// FilamentService wraps FilamentRepository with business logic and validation.
+type FilamentService struct {
+	repo *repositories.FilamentRepository
+}
+
+// NewFilamentService creates a FilamentService backed by the given repository.
+func NewFilamentService(repo *repositories.FilamentRepository) *FilamentService {
+	return &FilamentService{repo: repo}
+}
+
+// List returns paginated filament spools filtered by the given criteria.
+func (s *FilamentService) List(ctx context.Context, filter repositories.FilamentFilter) ([]models.FilamentSpool, int, error) {
+	return s.repo.GetAll(ctx, filter)
+}
+
+// GetByID returns a single filament spool by ID.
+func (s *FilamentService) GetByID(ctx context.Context, id int) (*models.FilamentSpool, error) {
+	return s.repo.GetByID(ctx, id)
+}
+
+// Create validates and creates a new filament spool.
+func (s *FilamentService) Create(ctx context.Context, spool *models.FilamentSpool) (*models.FilamentSpool, error) {
+	if err := validateFilamentSpool(spool); err != nil {
+		return nil, err
+	}
+	return s.repo.Create(ctx, spool)
+}
+
+// Update applies partial updates to a filament spool after validation.
+func (s *FilamentService) Update(ctx context.Context, id int, updates map[string]interface{}) (*models.FilamentSpool, error) {
+	return s.repo.Update(ctx, id, updates)
+}
+
+// SoftDelete marks a filament spool as deleted.
+func (s *FilamentService) SoftDelete(ctx context.Context, id int) (bool, error) {
+	return s.repo.SoftDelete(ctx, id)
+}
+
+// PrinterService wraps PrinterRepository.
+type PrinterService struct {
+	repo *repositories.PrinterRepository
+}
+
+// NewPrinterService creates a PrinterService backed by the given repository.
+func NewPrinterService(repo *repositories.PrinterRepository) *PrinterService {
+	return &PrinterService{repo: repo}
+}
+
+// List returns all printers.
+func (s *PrinterService) List(ctx context.Context) ([]models.Printer, error) {
+	return s.repo.GetAll(ctx)
+}
+
+// PrintJobService wraps PrintJobRepository.
+type PrintJobService struct {
+	repo *repositories.PrintJobRepository
+}
+
+// NewPrintJobService creates a PrintJobService backed by the given repository.
+func NewPrintJobService(repo *repositories.PrintJobRepository) *PrintJobService {
+	return &PrintJobService{repo: repo}
+}
+
+// List returns paginated print jobs filtered by the given criteria.
+func (s *PrintJobService) List(ctx context.Context, filter repositories.PrintJobFilter) ([]models.PrintJob, int, error) {
+	return s.repo.GetAll(ctx, filter)
+}
+
+// GetByID returns a single print job by ID.
+func (s *PrintJobService) GetByID(ctx context.Context, id int) (*models.PrintJob, error) {
+	return s.repo.GetByID(ctx, id)
+}

backend/internal/services/validation.go

@@ -0,0 +1,74 @@
+package services
+
+import (
+	"errors"
+	"fmt"
+	"regexp"
+
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/dtos"
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/models"
+)
+
+// colorHexPattern validates hex color strings like #FF0000 or #ff0000.
+var colorHexPattern = regexp.MustCompile(`^#[0-9A-Fa-f]{6}$`)
+
+// validateFilamentSpool performs validation on a FilamentSpool entity.
+// Returns a descriptive error on failure.
+func validateFilamentSpool(s *models.FilamentSpool) error {
+	if s.Name == "" {
+		return errors.New("name is required")
+	}
+	if s.MaterialBaseID <= 0 {
+		return errors.New("material_base_id is required")
+	}
+	if s.MaterialFinishID <= 0 {
+		return errors.New("material_finish_id is required")
+	}
+	if !colorHexPattern.MatchString(s.ColorHex) {
+		return fmt.Errorf("color_hex must be a valid hex color (e.g., #FF0000)")
+	}
+	if s.InitialGrams <= 0 {
+		return errors.New("initial_grams must be greater than 0")
+	}
+	if s.RemainingGrams < 0 {
+		return errors.New("remaining_grams must be >= 0")
+	}
+	return nil
+}
+
+// ValidateCreateFilamentRequest validates a creation DTO.
+func ValidateCreateFilamentRequest(req dtos.CreateFilamentRequest) error {
+	if req.Name == "" {
+		return errors.New("name is required")
+	}
+	if req.MaterialBaseID <= 0 {
+		return errors.New("material_base_id is required")
+	}
+	if req.MaterialFinishID <= 0 {
+		return errors.New("material_finish_id is required")
+	}
+	if !colorHexPattern.MatchString(req.ColorHex) {
+		return fmt.Errorf("color_hex must be a valid hex color (e.g., #FF0000)")
+	}
+	if req.InitialGrams <= 0 {
+		return errors.New("initial_grams must be greater than 0")
+	}
+	if req.RemainingGrams < 0 {
+		return errors.New("remaining_grams must be >= 0")
+	}
+	return nil
+}
+
+// ValidateUpdateFilamentRequest validates partial update fields.
+func ValidateUpdateFilamentRequest(req dtos.UpdateFilamentRequest) error {
+	if req.ColorHex != nil && !colorHexPattern.MatchString(*req.ColorHex) {
+		return fmt.Errorf("color_hex must be a valid hex color (e.g., #FF0000)")
+	}
+	if req.InitialGrams != nil && *req.InitialGrams <= 0 {
+		return errors.New("initial_grams must be greater than 0")
+	}
+	if req.RemainingGrams != nil && *req.RemainingGrams < 0 {
+		return errors.New("remaining_grams must be >= 0")
+	}
+	return nil
+}

backend/internal/sse/broadcaster.go

@@ -0,0 +1,133 @@
+package sse
+
+import (
+	"log/slog"
+	"sync"
+)
+
+// client represents a single SSE subscriber — identified by its send channel.
+type client struct {
+	ch chan string
+}
+
+// Broadcaster receives Events on its input channel and fans them out to every
+// connected client. Subscribe adds a new client; Unsubscribe removes one.
+// Start must be called before the broadcaster accepts events.
+type Broadcaster struct {
+	input       chan Event
+	subscribe   chan client
+	unsubscribe chan client
+	clients     map[chan string]struct{}
+	done        chan struct{}
+	once        sync.Once
+}
+
+// NewBroadcaster creates a Broadcaster. bufSize controls the buffer depth for
+// the input channel as well as for each per-client outbound channel.
+func NewBroadcaster(bufSize int) *Broadcaster {
+	if bufSize <= 0 {
+		bufSize = 64
+	}
+	return &Broadcaster{
+		input:       make(chan Event, bufSize),
+		subscribe:   make(chan client),
+		unsubscribe: make(chan client),
+		clients:     make(map[chan string]struct{}),
+		done:        make(chan struct{}),
+	}
+}
+
+// Publish pushes an event into the broadcaster. Safe for concurrent use.
+func (b *Broadcaster) Publish(ev Event) {
+	select {
+	case b.input <- ev:
+	case <-b.done:
+		// Silently drop during shutdown.
+	}
+}
+
+// Start launches the broadcaster's fan-out loop in a goroutine.
+// It must be called before Publish is used.
+func (b *Broadcaster) Start() {
+	go b.loop()
+}
+
+// Stop terminates the fan-out loop and closes all client channels.
+// It is safe to call multiple times.
+func (b *Broadcaster) Stop() {
+	b.once.Do(func() {
+		close(b.done)
+	})
+}
+
+// Subscribe returns a new client channel that receives SSE-formatted strings.
+func (b *Broadcaster) Subscribe() chan string {
+	c := client{ch: make(chan string, 64)}
+	select {
+	case b.subscribe <- c:
+	case <-b.done:
+		// Broadcaster already stopped — return a closed chan so the handler
+		// can bail out quickly.
+		ch := make(chan string)
+		close(ch)
+		return ch
+	}
+	return c.ch
+}
+
+// Unsubscribe removes a client channel and closes it.
+func (b *Broadcaster) Unsubscribe(ch chan string) {
+	c := client{ch: ch}
+	select {
+	case b.unsubscribe <- c:
+	case <-b.done:
+		// Already shutting down — channels will be cleaned up by Stop.
+	}
+}
+
+// loop is the core fan-out goroutine.
+func (b *Broadcaster) loop() {
+	for {
+		select {
+		case ev := <-b.input:
+			sse := ev.toSSE()
+			for ch := range b.clients {
+				// Non-blocking send — slow clients are dropped.
+				select {
+				case ch <- sse:
+				default:
+					slog.Warn("sse broadcaster: dropping event for slow client", "type", ev.Type)
+				}
+			}
+
+		case c := <-b.subscribe:
+			b.clients[c.ch] = struct{}{}
+			slog.Debug("sse broadcaster: client connected", "total_clients", len(b.clients))
+
+		case c := <-b.unsubscribe:
+			if _, ok := b.clients[c.ch]; ok {
+				delete(b.clients, c.ch)
+				close(c.ch)
+				slog.Debug("sse broadcaster: client disconnected", "total_clients", len(b.clients))
+			}
+
+		case <-b.done:
+			// Drain remaining events in input before shutting down.
+			for ev := range b.input {
+				sse := ev.toSSE()
+				for ch := range b.clients {
+					select {
+					case ch <- sse:
+					default:
+					}
+				}
+			}
+			// Close all remaining client channels.
+			for ch := range b.clients {
+				close(ch)
+			}
+			b.clients = nil
+			return
+		}
+	}
+}

backend/internal/sse/events.go

@@ -0,0 +1,92 @@
+// Package sse provides Server-Sent Events infrastructure for real-time updates.
+// Includes event types, a central broadcaster, and an HTTP handler.
+package sse
+
+import (
+	"encoding/json"
+	"time"
+)
+
+// EventType identifies the category of an SSE event.
+type EventType string
+
+const (
+	EventPrinterStatus  EventType = "printer.status"
+	EventJobStarted     EventType = "job.started"
+	EventJobCompleted   EventType = "job.completed"
+	EventFilamentLow    EventType = "filament.low"
+)
+
+// Event is a JSON-serializable SSE event pushed through the broadcaster.
+type Event struct {
+	Type      EventType       `json:"type"`
+	Payload   json.RawMessage `json:"payload"`
+	Timestamp time.Time       `json:"timestamp"`
+}
+
+// PrinterStatusPayload carries printer online/offline/printing state.
+type PrinterStatusPayload struct {
+	PrinterID   int    `json:"printer_id"`
+	PrinterName string `json:"printer_name"`
+	Status      string `json:"status"` // "online", "offline", "printing"
+}
+
+// JobStartedPayload carries initial print job info.
+type JobStartedPayload struct {
+	JobID      int    `json:"job_id"`
+	JobName    string `json:"job_name"`
+	PrinterID  int    `json:"printer_id"`
+	SpoolID    *int   `json:"spool_id,omitempty"`
+}
+
+// JobCompletedPayload carries final print job data including usage.
+type JobCompletedPayload struct {
+	JobID           int     `json:"job_id"`
+	JobName         string  `json:"job_name"`
+	PrinterID       int     `json:"printer_id"`
+	DurationSeconds *int    `json:"duration_seconds,omitempty"`
+	TotalGramsUsed  *float64 `json:"total_grams_used,omitempty"`
+	TotalCostUSD    *float64 `json:"total_cost_usd,omitempty"`
+}
+
+// FilamentLowPayload alerts that a spool is below its threshold.
+type FilamentLowPayload struct {
+	SpoolID       int    `json:"spool_id"`
+	SpoolName     string `json:"spool_name"`
+	RemainingGrams int   `json:"remaining_grams"`
+	ThresholdGrams int   `json:"threshold_grams"`
+}
+
+// NewEvent creates an Event with the current timestamp from a typed payload.
+func NewEvent(eventType EventType, payload any) (Event, error) {
+	raw, err := json.Marshal(payload)
+	if err != nil {
+		return Event{}, err
+	}
+	return Event{
+		Type:      eventType,
+		Payload:   raw,
+		Timestamp: time.Now().UTC(),
+	}, nil
+}
+
+// MustEvent creates an Event and panics on marshal failure (for use with
+// known-good payloads in tests and internal wiring).
+func MustEvent(eventType EventType, payload any) Event {
+	ev, err := NewEvent(eventType, payload)
+	if err != nil {
+		panic("sse.MustEvent: failed to marshal payload: " + err.Error())
+	}
+	return ev
+}
+
+// toSSE formats this Event as a standard SSE message string ready to be
+// written to a response writer. The format is:
+//
+//	event: <type>
+//	data: <json>
+//
+func (e Event) toSSE() string {
+	data, _ := json.Marshal(e)
+	return "event: " + string(e.Type) + "\n" + "data: " + string(data) + "\n\n"
+}

backend/internal/sse/handler.go

@@ -0,0 +1,59 @@
+package sse
+
+import (
+	"net/http"
+)
+
+// Handler is the HTTP handler for the GET /api/events SSE stream.
+// It registers a client with the broadcaster, streams events as they arrive,
+// and unregisters on disconnect.
+type Handler struct {
+	bc *Broadcaster
+}
+
+// NewHandler creates a Handler backed by the given Broadcaster.
+func NewHandler(bc *Broadcaster) *Handler {
+	return &Handler{bc: bc}
+}
+
+// ServeHTTP implements the SSE streaming endpoint.
+// Flusher is required; clients that do not support flushing receive a 501.
+func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	flusher, ok := w.(http.Flusher)
+	if !ok {
+		http.Error(w, "streaming not supported", http.StatusNotImplemented)
+		return
+	}
+
+	// SSE-specific headers
+	w.Header().Set("Content-Type", "text/event-stream")
+	w.Header().Set("Cache-Control", "no-cache")
+	w.Header().Set("Connection", "keep-alive")
+	w.Header().Set("X-Accel-Buffering", "no") // Disable nginx buffering
+
+	// Write headers immediately
+	flusher.Flush()
+
+	// Subscribe to the broadcaster
+	ch := h.bc.Subscribe()
+	defer h.bc.Unsubscribe(ch)
+
+	// Use request context for cancellation when the client disconnects.
+	ctx := r.Context()
+
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case msg, ok := <-ch:
+			if !ok {
+				return
+			}
+			_, err := w.Write([]byte(msg))
+			if err != nil {
+				return
+			}
+			flusher.Flush()
+		}
+	}
+}

backend/migrations/000001_initial_schema.down.sql

@@ -0,0 +1,19 @@
+-- Migration: 000001_initial_schema (rollback)
+-- Description: Drop all tables and indexes created in the initial schema migration
+-- Author: Hex
+-- Date: 2026-05-06
+
+BEGIN;
+
+DROP TABLE IF EXISTS usage_logs        CASCADE;
+DROP TABLE IF EXISTS print_jobs        CASCADE;
+DROP TABLE IF EXISTS filament_spools   CASCADE;
+DROP TABLE IF EXISTS printers          CASCADE;
+DROP TABLE IF EXISTS settings          CASCADE;
+DROP TABLE IF EXISTS material_modifiers CASCADE;
+DROP TABLE IF EXISTS material_finishes  CASCADE;
+DROP TABLE IF EXISTS material_bases     CASCADE;
+DROP TABLE IF EXISTS job_statuses       CASCADE;
+DROP TABLE IF EXISTS printer_types      CASCADE;
+
+COMMIT;

backend/migrations/000001_initial_schema.up.sql

@@ -0,0 +1,231 @@
+-- Migration: 000001_initial_schema
+-- Description: Create initial Extrudex schema — lookup tables, core entities, and settings
+-- Author: Hex
+-- Date: 2026-05-06
+--
+-- Design decisions:
+--   - Lookup tables for material_base, material_finish, material_modifier (no free-text enums)
+--   - Lookup tables for printer_type and job_status (extensible, no hard-coded enum values)
+--   - FK ON DELETE: RESTRICT on critical parents (material_base, material_finish, printer),
+--     SET NULL on optional parents (modifier, spool on print_jobs),
+--     CASCADE for usage_logs when parent job is deleted
+--   - Soft-delete (deleted_at) on spools and print_jobs for safety
+--   - JSONB config column on settings for flexible app-wide configuration
+--   - All identifiers snake_case per project convention
+
+BEGIN;
+
+-- ============================================================================
+-- Lookup Tables
+-- ============================================================================
+
+-- Printer types (fdm, resin, etc.) — extensible, not a raw enum
+CREATE TABLE printer_types (
+    id          SERIAL PRIMARY KEY,
+    name        VARCHAR(50) NOT NULL UNIQUE,
+    created_at  TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at  TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+-- Job statuses (pending, printing, paused, completed, failed, cancelled)
+CREATE TABLE job_statuses (
+    id          SERIAL PRIMARY KEY,
+    name        VARCHAR(50) NOT NULL UNIQUE,
+    created_at  TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at  TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+-- Material base types (PLA, PETG, ABS, TPU, ASA, Nylon, PC)
+CREATE TABLE material_bases (
+    id                  SERIAL PRIMARY KEY,
+    name                VARCHAR(100) NOT NULL UNIQUE,
+    density_g_cm3       DECIMAL(5,3) NOT NULL,
+    extrusion_temp_min  INT,
+    extrusion_temp_max  INT,
+    bed_temp_min        INT,
+    bed_temp_max        INT,
+    created_at          TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at          TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+-- Material finishes (Basic, Silk, Matte, Glossy, Satin)
+CREATE TABLE material_finishes (
+    id          SERIAL PRIMARY KEY,
+    name        VARCHAR(100) NOT NULL UNIQUE,
+    description TEXT,
+    created_at  TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at  TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+-- Material modifiers (Wood-Filled, Carbon Fiber, Glow-in-Dark, Marble)
+CREATE TABLE material_modifiers (
+    id          SERIAL PRIMARY KEY,
+    name        VARCHAR(100) NOT NULL UNIQUE,
+    description TEXT,
+    created_at  TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at  TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+-- ============================================================================
+-- Core Entity Tables
+-- ============================================================================
+
+-- 3D printers in the fleet
+CREATE TABLE printers (
+    id                  SERIAL PRIMARY KEY,
+    name                VARCHAR(255) NOT NULL,
+    printer_type_id     INT NOT NULL,
+    manufacturer        VARCHAR(255),
+    model               VARCHAR(255),
+    moonraker_url       VARCHAR(512),
+    moonraker_api_key   VARCHAR(512),
+    mqtt_broker_host    VARCHAR(255),
+    mqtt_topic_prefix   VARCHAR(255),
+    mqtt_tls_enabled    BOOLEAN NOT NULL DEFAULT FALSE,
+    is_active           BOOLEAN NOT NULL DEFAULT TRUE,
+    created_at          TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at          TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+
+    CONSTRAINT fk_printers_printer_type
+        FOREIGN KEY (printer_type_id) REFERENCES printer_types(id)
+        ON DELETE RESTRICT
+);
+
+-- Filament spools — the core inventory item
+CREATE TABLE filament_spools (
+    id                      SERIAL PRIMARY KEY,
+    name                    VARCHAR(255) NOT NULL,
+    material_base_id        INT NOT NULL,
+    material_finish_id      INT NOT NULL DEFAULT 1,  -- "Basic" (seed data populates this first)
+    material_modifier_id    INT,
+    color_hex               VARCHAR(7) NOT NULL CHECK (color_hex ~ '^#[0-9A-Fa-f]{6}$'),
+    brand                   VARCHAR(255),
+    diameter_mm             DECIMAL(4,2) NOT NULL DEFAULT 1.75,
+    initial_grams           INT NOT NULL CHECK (initial_grams > 0),
+    remaining_grams         INT NOT NULL CHECK (remaining_grams >= 0),
+    spool_weight_grams      INT,  -- measured empty-spool weight (tare), nullable
+    cost_usd                DECIMAL(10,2),
+    low_stock_threshold_grams INT NOT NULL DEFAULT 50,
+    notes                   TEXT,
+    barcode                 VARCHAR(255) UNIQUE,
+    deleted_at              TIMESTAMPTZ,
+    created_at              TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at              TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+
+    CONSTRAINT fk_spools_material_base
+        FOREIGN KEY (material_base_id) REFERENCES material_bases(id)
+        ON DELETE RESTRICT,
+
+    CONSTRAINT fk_spools_material_finish
+        FOREIGN KEY (material_finish_id) REFERENCES material_finishes(id)
+        ON DELETE RESTRICT,
+
+    CONSTRAINT fk_spools_material_modifier
+        FOREIGN KEY (material_modifier_id) REFERENCES material_modifiers(id)
+        ON DELETE SET NULL
+);
+
+-- Print jobs — each job is one print on one printer
+CREATE TABLE print_jobs (
+    id                      SERIAL PRIMARY KEY,
+    printer_id              INT NOT NULL,
+    filament_spool_id       INT,  -- nullable: a job may use multiple spools (captured in usage_logs)
+    job_name                VARCHAR(255) NOT NULL,
+    file_name               VARCHAR(512),
+    job_status_id           INT NOT NULL DEFAULT 1,  -- "pending"
+    started_at              TIMESTAMPTZ,
+    completed_at            TIMESTAMPTZ,
+    duration_seconds        INT,
+    estimated_duration_seconds INT,
+    total_mm_extruded       DECIMAL(12,2),
+    total_grams_used        DECIMAL(10,2),
+    total_cost_usd          DECIMAL(10,4),
+    notes                   TEXT,
+    deleted_at              TIMESTAMPTZ,
+    created_at              TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at              TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+
+    CONSTRAINT fk_print_jobs_printer
+        FOREIGN KEY (printer_id) REFERENCES printers(id)
+        ON DELETE RESTRICT,
+
+    CONSTRAINT fk_print_jobs_spool
+        FOREIGN KEY (filament_spool_id) REFERENCES filament_spools(id)
+        ON DELETE SET NULL,
+
+    CONSTRAINT fk_print_jobs_status
+        FOREIGN KEY (job_status_id) REFERENCES job_statuses(id)
+        ON DELETE RESTRICT
+);
+
+-- Usage logs — granular tracking of filament consumed per job, per spool
+CREATE TABLE usage_logs (
+    id                  SERIAL PRIMARY KEY,
+    print_job_id        INT NOT NULL,
+    filament_spool_id   INT NOT NULL,
+    mm_extruded         DECIMAL(12,2) NOT NULL CHECK (mm_extruded > 0),
+    grams_used          DECIMAL(10,2) NOT NULL CHECK (grams_used > 0),
+    cost_usd            DECIMAL(10,4),
+    logged_at           TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    created_at          TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+
+    CONSTRAINT fk_usage_logs_print_job
+        FOREIGN KEY (print_job_id) REFERENCES print_jobs(id)
+        ON DELETE CASCADE,
+
+    CONSTRAINT fk_usage_logs_spool
+        FOREIGN KEY (filament_spool_id) REFERENCES filament_spools(id)
+        ON DELETE RESTRICT
+);
+
+-- ============================================================================
+-- Application Settings
+-- ============================================================================
+
+CREATE TABLE settings (
+    id          SERIAL PRIMARY KEY,
+    key         VARCHAR(255) NOT NULL UNIQUE,
+    value       JSONB NOT NULL,
+    description TEXT,
+    created_at  TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at  TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+-- ============================================================================
+-- Indexes
+-- ============================================================================
+
+-- Filament spools — query patterns: lookup by material, low-stock scans, barcode scans
+CREATE INDEX ix_spools_material_base_id     ON filament_spools(material_base_id);
+CREATE INDEX ix_spools_material_finish_id   ON filament_spools(material_finish_id);
+CREATE INDEX ix_spools_material_modifier_id ON filament_spools(material_modifier_id);
+CREATE INDEX ix_spools_remaining_grams      ON filament_spools(remaining_grams)
+    WHERE deleted_at IS NULL;  -- partial index: only active spools for low-stock queries
+CREATE INDEX ix_spools_barcode              ON filament_spools(barcode)
+    WHERE barcode IS NOT NULL AND deleted_at IS NULL;
+CREATE INDEX ix_spools_deleted_at           ON filament_spools(deleted_at)
+    WHERE deleted_at IS NOT NULL;  -- small index for soft-delete filtering
+
+-- Printers
+CREATE INDEX ix_printers_printer_type_id ON printers(printer_type_id);
+CREATE INDEX ix_printers_is_active       ON printers(is_active)
+    WHERE is_active = TRUE;  -- partial index for fleet dashboard queries
+
+-- Print jobs — query by printer, status, date range, and soft-delete filter
+CREATE INDEX ix_print_jobs_printer_id   ON print_jobs(printer_id);
+CREATE INDEX ix_print_jobs_spool_id     ON print_jobs(filament_spool_id)
+    WHERE filament_spool_id IS NOT NULL;
+CREATE INDEX ix_print_jobs_status_id    ON print_jobs(job_status_id);
+CREATE INDEX ix_print_jobs_created_at   ON print_jobs(created_at DESC);
+CREATE INDEX ix_print_jobs_deleted_at   ON print_jobs(deleted_at)
+    WHERE deleted_at IS NOT NULL;
+
+-- Usage logs — always queried by job or spool
+CREATE INDEX ix_usage_logs_print_job_id ON usage_logs(print_job_id);
+CREATE INDEX ix_usage_logs_spool_id     ON usage_logs(filament_spool_id);
+CREATE INDEX ix_usage_logs_logged_at    ON usage_logs(logged_at DESC);
+
+-- Settings — key lookups
+CREATE INDEX ix_settings_key ON settings(key);
+
+COMMIT;

backend/migrations/000002_seed_data.down.sql

@@ -0,0 +1,15 @@
+-- Migration: 000002_seed_data (rollback)
+-- Description: Remove seed data inserted in 000002
+-- Author: Hex
+-- Date: 2026-05-06
+
+BEGIN;
+
+DELETE FROM settings            WHERE key IN ('default_low_stock_threshold_grams', 'default_diameter_mm', 'filament_cross_section_area_mm2');
+DELETE FROM material_modifiers  WHERE id IN (1, 2, 3, 4);
+DELETE FROM material_finishes   WHERE id IN (1, 2, 3, 4, 5);
+DELETE FROM material_bases      WHERE id IN (1, 2, 3, 4, 5, 6, 7);
+DELETE FROM job_statuses        WHERE id IN (1, 2, 3, 4, 5, 6);
+DELETE FROM printer_types       WHERE id IN (1, 2);
+
+COMMIT;

backend/migrations/000002_seed_data.up.sql

@@ -0,0 +1,95 @@
+-- Seed Data: Extrudex common reference data
+-- Author: Hex
+-- Date: 2026-05-06
+--
+-- IMPORTANT: IDs are explicitly assigned to satisfy the DEFAULT constraints:
+--   - filament_spools.material_finish_id  DEFAULT 1  ("Basic")
+--   - print_jobs.job_status_id            DEFAULT 1  ("pending")
+--
+-- Density values sourced from common manufacturer specifications.
+-- Temperature ranges are conservative/typical; users can override per-spool.
+
+BEGIN;
+
+-- ============================================================================
+-- Printer Types
+-- ============================================================================
+
+INSERT INTO printer_types (id, name) VALUES
+    (1, 'fdm'),
+    (2, 'resin')
+ON CONFLICT (id) DO NOTHING;
+
+-- Reset the sequence so future inserts start after our explicit IDs
+SELECT setval('printer_types_id_seq', GREATEST(2, (SELECT MAX(id) FROM printer_types)));
+
+-- ============================================================================
+-- Job Statuses
+-- ============================================================================
+
+INSERT INTO job_statuses (id, name) VALUES
+    (1, 'pending'),
+    (2, 'printing'),
+    (3, 'paused'),
+    (4, 'completed'),
+    (5, 'failed'),
+    (6, 'cancelled')
+ON CONFLICT (id) DO NOTHING;
+
+SELECT setval('job_statuses_id_seq', GREATEST(6, (SELECT MAX(id) FROM job_statuses)));
+
+-- ============================================================================
+-- Material Bases (common filament types)
+-- ============================================================================
+
+INSERT INTO material_bases (id, name, density_g_cm3, extrusion_temp_min, extrusion_temp_max, bed_temp_min, bed_temp_max) VALUES
+    (1, 'PLA',   1.24, 190, 220,  0,  60),
+    (2, 'PETG',  1.27, 230, 250, 70,  90),
+    (3, 'ABS',   1.04, 230, 260, 90, 110),
+    (4, 'TPU',   1.21, 220, 250,  0,  60),
+    (5, 'ASA',   1.07, 240, 260, 90, 110),
+    (6, 'Nylon', 1.14, 240, 280, 70, 100),
+    (7, 'PC',    1.20, 260, 310, 90, 120)
+ON CONFLICT (id) DO NOTHING;
+
+SELECT setval('material_bases_id_seq', GREATEST(7, (SELECT MAX(id) FROM material_bases)));
+
+-- ============================================================================
+-- Material Finishes
+-- ============================================================================
+-- ID 1 = "Basic" is the default for new spools (DEFAULT 1 constraint)
+
+INSERT INTO material_finishes (id, name, description) VALUES
+    (1, 'Basic',  'Standard solid-color filament with no special finish'),
+    (2, 'Silk',   'Glossy silk-like sheen, often used for decorative prints'),
+    (3, 'Matte',  'Flat non-reflective surface finish'),
+    (4, 'Glossy', 'High-shine reflective surface'),
+    (5, 'Satin',  'Semi-gloss between matte and glossy')
+ON CONFLICT (id) DO NOTHING;
+
+SELECT setval('material_finishes_id_seq', GREATEST(5, (SELECT MAX(id) FROM material_finishes)));
+
+-- ============================================================================
+-- Material Modifiers
+-- ============================================================================
+
+INSERT INTO material_modifiers (id, name, description) VALUES
+    (1, 'Wood-Filled',   'Contains wood fibers for natural wood-like appearance and texture'),
+    (2, 'Carbon Fiber',  'Reinforced with carbon fibers for increased stiffness and strength'),
+    (3, 'Glow-in-Dark',  'Phosphorescent additive that glows after exposure to light'),
+    (4, 'Marble',        'Contains specks for a stone-like marble appearance')
+ON CONFLICT (id) DO NOTHING;
+
+SELECT setval('material_modifiers_id_seq', GREATEST(4, (SELECT MAX(id) FROM material_modifiers)));
+
+-- ============================================================================
+-- Default Application Settings
+-- ============================================================================
+
+INSERT INTO settings (key, value, description) VALUES
+    ('default_low_stock_threshold_grams', '50', 'Default grams threshold for low-stock alerts on new spools'),
+    ('default_diameter_mm', '1.75', 'Default filament diameter for new spools (1.75mm is the modern standard)'),
+    ('filament_cross_section_area_mm2', '2.405', 'Cross-sectional area for 1.75mm filament: π × (1.75/2)²')
+ON CONFLICT (key) DO NOTHING;
+
+COMMIT;

frontend/.dockerignore

@@ -1,11 +0,0 @@
-node_modules
-dist
-.git
-.gitignore
-.angular
-.vscode
-*.md
-.editorconfig
-.prettierrc
-src/test.ts
-**/*.spec.ts

frontend/.editorconfig

@@ -1,17 +0,0 @@
-# Editor configuration, see https://editorconfig.org
-root = true
-
-[*]
-charset = utf-8
-indent_style = space
-indent_size = 2
-insert_final_newline = true
-trim_trailing_whitespace = true
-
-[*.ts]
-quote_type = single
-ij_typescript_use_double_quotes = false
-
-[*.md]
-max_line_length = off
-trim_trailing_whitespace = false

frontend/.gitignore

@@ -1,44 +0,0 @@
-# See https://docs.github.com/get-started/getting-started-with-git/ignoring-files for more about ignoring files.
-
-# Compiled output
-/dist
-/tmp
-/out-tsc
-/bazel-out
-
-# Node
-/node_modules
-npm-debug.log
-yarn-error.log
-
-# IDEs and editors
-.idea/
-.project
-.classpath
-.c9/
-*.launch
-.settings/
-*.sublime-workspace
-
-# Visual Studio Code
-.vscode/*
-!.vscode/settings.json
-!.vscode/tasks.json
-!.vscode/launch.json
-!.vscode/extensions.json
-!.vscode/mcp.json
-.history/*
-
-# Miscellaneous
-/.angular/cache
-.sass-cache/
-/connect.lock
-/coverage
-/libpeerconnection.log
-testem.log
-/typings
-__screenshots__/
-
-# System files
-.DS_Store
-Thumbs.db

frontend/.prettierrc

@@ -1,12 +0,0 @@
-{
-  "printWidth": 100,
-  "singleQuote": true,
-  "overrides": [
-    {
-      "files": "*.html",
-      "options": {
-        "parser": "angular"
-      }
-    }
-  ]
-}

frontend/.vscode/extensions.json

@@ -1,4 +0,0 @@
-{
-  // For more information, visit: https://go.microsoft.com/fwlink/?linkid=827846
-  "recommendations": ["angular.ng-template"]
-}

frontend/.vscode/launch.json

@@ -1,20 +0,0 @@
-{
-  // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
-  "version": "0.2.0",
-  "configurations": [
-    {
-      "name": "ng serve",
-      "type": "chrome",
-      "request": "launch",
-      "preLaunchTask": "npm: start",
-      "url": "http://localhost:4200/"
-    },
-    {
-      "name": "ng test",
-      "type": "chrome",
-      "request": "launch",
-      "preLaunchTask": "npm: test",
-      "url": "http://localhost:9876/debug.html"
-    }
-  ]
-}

frontend/.vscode/mcp.json

@@ -1,9 +0,0 @@
-{
-  // For more information, visit: https://angular.dev/ai/mcp
-  "servers": {
-    "angular-cli": {
-      "command": "npx",
-      "args": ["-y", "@angular/cli", "mcp"]
-    }
-  }
-}

frontend/.vscode/tasks.json

@@ -1,42 +0,0 @@
-{
-  // For more information, visit: https://go.microsoft.com/fwlink/?LinkId=733558
-  "version": "2.0.0",
-  "tasks": [
-    {
-      "type": "npm",
-      "script": "start",
-      "isBackground": true,
-      "problemMatcher": {
-        "owner": "typescript",
-        "pattern": "$tsc",
-        "background": {
-          "activeOnStart": true,
-          "beginsPattern": {
-            "regexp": "Changes detected"
-          },
-          "endsPattern": {
-            "regexp": "bundle generation (complete|failed)"
-          }
-        }
-      }
-    },
-    {
-      "type": "npm",
-      "script": "test",
-      "isBackground": true,
-      "problemMatcher": {
-        "owner": "typescript",
-        "pattern": "$tsc",
-        "background": {
-          "activeOnStart": true,
-          "beginsPattern": {
-            "regexp": "Changes detected"
-          },
-          "endsPattern": {
-            "regexp": "bundle generation (complete|failed)"
-          }
-        }
-      }
-    }
-  ]
-}

frontend/Dockerfile

@@ -1,28 +1,14 @@
-# Stage 1: Build the Angular application
-FROM node:22-alpine AS build
-
+# Build stage
+FROM node:22-alpine AS builder
 WORKDIR /app
-
-# Copy package files first for better layer caching
-COPY package.json package-lock.json ./
+COPY package*.json ./
 RUN npm ci
-
-# Copy source and build
 COPY . .
-RUN npx ng build --configuration production
+RUN npm run build
 
-# Stage 2: Serve static files with nginx
+# Serve stage
 FROM nginx:alpine
-
-# Remove default nginx config
-RUN rm /etc/nginx/conf.d/default.conf
-
-# Copy custom nginx config
+COPY --from=builder /app/dist /usr/share/nginx/html
 COPY nginx.conf /etc/nginx/conf.d/default.conf
-
-# Copy built Angular artifacts from build stage
-COPY --from=build /app/dist/frontend/browser /usr/share/nginx/html
-
 EXPOSE 80
-
-CMD ["nginx", "-g", "daemon off;"]
+CMD ["nginx", "-g", "daemon off;"]

frontend/README.md

@@ -1,59 +0,0 @@
-# Frontend
-
-This project was generated using [Angular CLI](https://github.com/angular/angular-cli) version 21.2.8.
-
-## Development server
-
-To start a local development server, run:
-
-```bash
-ng serve
-```
-
-Once the server is running, open your browser and navigate to `http://localhost:4200/`. The application will automatically reload whenever you modify any of the source files.
-
-## Code scaffolding
-
-Angular CLI includes powerful code scaffolding tools. To generate a new component, run:
-
-```bash
-ng generate component component-name
-```
-
-For a complete list of available schematics (such as `components`, `directives`, or `pipes`), run:
-
-```bash
-ng generate --help
-```
-
-## Building
-
-To build the project run:
-
-```bash
-ng build
-```
-
-This will compile your project and store the build artifacts in the `dist/` directory. By default, the production build optimizes your application for performance and speed.
-
-## Running unit tests
-
-To execute unit tests with the [Vitest](https://vitest.dev/) test runner, use the following command:
-
-```bash
-ng test
-```
-
-## Running end-to-end tests
-
-For end-to-end (e2e) testing, run:
-
-```bash
-ng e2e
-```
-
-Angular CLI does not come with an end-to-end testing framework by default. You can choose one that suits your needs.
-
-## Additional Resources
-
-For more information on using the Angular CLI, including detailed command references, visit the [Angular CLI Overview and Command Reference](https://angular.dev/tools/cli) page.

frontend/angular.json

@@ -1,78 +0,0 @@
-{
-  "$schema": "./node_modules/@angular/cli/lib/config/schema.json",
-  "version": 1,
-  "cli": {
-    "packageManager": "npm"
-  },
-  "newProjectRoot": "projects",
-  "projects": {
-    "frontend": {
-      "projectType": "application",
-      "schematics": {
-        "@schematics/angular:component": {
-          "style": "scss"
-        }
-      },
-      "root": "",
-      "sourceRoot": "src",
-      "prefix": "app",
-      "architect": {
-        "build": {
-          "builder": "@angular/build:application",
-          "options": {
-            "browser": "src/main.ts",
-            "tsConfig": "tsconfig.app.json",
-            "inlineStyleLanguage": "scss",
-            "assets": [
-              {
-                "glob": "**/*",
-                "input": "public"
-              }
-            ],
-            "styles": [
-              "src/styles.scss"
-            ]
-          },
-          "configurations": {
-            "production": {
-              "budgets": [
-                {
-                  "type": "initial",
-                  "maximumWarning": "500kB",
-                  "maximumError": "1MB"
-                },
-                {
-                  "type": "anyComponentStyle",
-                  "maximumWarning": "4kB",
-                  "maximumError": "8kB"
-                }
-              ],
-              "outputHashing": "all"
-            },
-            "development": {
-              "optimization": false,
-              "extractLicenses": false,
-              "sourceMap": true
-            }
-          },
-          "defaultConfiguration": "production"
-        },
-        "serve": {
-          "builder": "@angular/build:dev-server",
-          "configurations": {
-            "production": {
-              "buildTarget": "frontend:build:production"
-            },
-            "development": {
-              "buildTarget": "frontend:build:development"
-            }
-          },
-          "defaultConfiguration": "development"
-        },
-        "test": {
-          "builder": "@angular/build:unit-test"
-        }
-      }
-    }
-  }
-}

frontend/eslint.config.js

@@ -0,0 +1,28 @@
+import js from '@eslint/js'
+import globals from 'globals'
+import reactHooks from 'eslint-plugin-react-hooks'
+import reactRefresh from 'eslint-plugin-react-refresh'
+import tseslint from 'typescript-eslint'
+
+export default tseslint.config(
+  { ignores: ['dist'] },
+  {
+    extends: [js.configs.recommended, ...tseslint.configs.recommended],
+    files: ['**/*.{ts,tsx}'],
+    languageOptions: {
+      ecmaVersion: 2020,
+      globals: globals.browser,
+    },
+    plugins: {
+      'react-hooks': reactHooks,
+      'react-refresh': reactRefresh,
+    },
+    rules: {
+      ...reactHooks.configs.recommended.rules,
+      'react-refresh/only-export-components': [
+        'warn',
+        { allowConstantExport: true },
+      ],
+    },
+  },
+)

frontend/index.html

@@ -0,0 +1,13 @@
+<!doctype html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <link rel="icon" type="image/svg+xml" href="/vite.svg" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <title>Extrudex</title>
+  </head>
+  <body>
+    <div id="root"></div>
+    <script type="module" src="/src/main.tsx"></script>
+  </body>
+</html>

frontend/nginx.conf

@@ -1,42 +1,23 @@
 server {
     listen 80;
     server_name _;
+
     root /usr/share/nginx/html;
     index index.html;
 
-    # Gzip compression
-    gzip on;
-    gzip_types text/plain text/css application/json application/javascript text/xml application/xml text/javascript;
-    gzip_min_length 256;
-
-    # Angular SPA — fallback to index.html for client-side routing
     location / {
         try_files $uri $uri/ /index.html;
     }
 
-    # Cache static assets aggressively
-    location ~* \.(js|css|png|jpg|jpeg|gif|ico|svg|woff2?|ttf|eot)$ {
-        expires 1y;
-        add_header Cache-Control "public, immutable";
-    }
-
-    # Proxy API requests to backend
-    # Uses resolver so nginx doesn't crash if backend isn't available at startup
-    resolver 127.0.0.11 valid=30s ipv6=off;
-    set $backend "extrudex-api:8080";
-
     location /api/ {
-        proxy_pass http://$backend;
+        proxy_pass http://backend:8080/api/;
+        proxy_http_version 1.1;
+        proxy_set_header Upgrade $http_upgrade;
+        proxy_set_header Connection 'upgrade';
         proxy_set_header Host $host;
+        proxy_cache_bypass $http_upgrade;
         proxy_set_header X-Real-IP $remote_addr;
         proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
         proxy_set_header X-Forwarded-Proto $scheme;
     }
-
-    # Health check endpoint
-    location /health {
-        access_log off;
-        return 200 "ok";
-        add_header Content-Type text/plain;
-    }
-}
+}

frontend/package.json

@@ -1,35 +1,35 @@
 {
-  "name": "frontend",
-  "version": "0.0.0",
-  "scripts": {
-    "ng": "ng",
-    "start": "ng serve",
-    "build": "ng build",
-    "watch": "ng build --watch --configuration development",
-    "test": "ng test"
-  },
+  "name": "extrudex-frontend",
   "private": true,
-  "packageManager": "npm@11.11.0",
+  "version": "0.0.1",
+  "type": "module",
+  "scripts": {
+    "dev": "vite",
+    "build": "tsc && vite build",
+    "lint": "eslint . --ext ts,tsx --report-unused-disable-directives --max-warnings 0",
+    "preview": "vite preview"
+  },
   "dependencies": {
-    "@angular/cdk": "^21.2.8",
-    "@angular/common": "^21.2.0",
-    "@angular/compiler": "^21.2.0",
-    "@angular/core": "^21.2.0",
-    "@angular/forms": "^21.2.0",
-    "@angular/material": "^21.2.8",
-    "@angular/platform-browser": "^21.2.0",
-    "@angular/router": "^21.2.0",
-    "rxjs": "~7.8.0",
-    "tslib": "^2.3.0"
+    "@tanstack/react-query": "^5.60.0",
+    "axios": "^1.7.0",
+    "lucide-react": "^0.460.0",
+    "react": "^19.0.0",
+    "react-dom": "^19.0.0",
+    "react-router-dom": "^7.0.0"
   },
   "devDependencies": {
-    "@angular/build": "^21.2.8",
-    "@angular/cli": "^21.2.8",
-    "@angular/compiler-cli": "^21.2.0",
-    "@vitest/browser-playwright": "^4.1.5",
-    "jsdom": "^28.0.0",
-    "prettier": "^3.8.1",
-    "typescript": "~5.9.2",
-    "vitest": "^4.0.8"
+    "@tailwindcss/postcss": "^4.2.4",
+    "@tailwindcss/vite": "^4.2.4",
+    "@types/react": "^19.0.0",
+    "@types/react-dom": "^19.0.0",
+    "@vitejs/plugin-react": "^4.3.0",
+    "autoprefixer": "^10.4.20",
+    "eslint": "^9.15.0",
+    "eslint-plugin-react-hooks": "^5.0.0",
+    "eslint-plugin-react-refresh": "^0.4.14",
+    "postcss": "^8.4.49",
+    "tailwindcss": "^4.0.0",
+    "typescript": "~5.6.0",
+    "vite": "^6.0.0"
   }
 }

frontend/postcss.config.js

@@ -0,0 +1,5 @@
+export default {
+  plugins: {
+    '@tailwindcss/postcss': {},
+  },
+}

frontend/src/App.tsx

@@ -0,0 +1,27 @@
+import { QueryClient, QueryClientProvider } from '@tanstack/react-query'
+import { BrowserRouter, Routes, Route } from 'react-router-dom'
+import Dashboard from './pages/Dashboard'
+import InventoryPage from './pages/InventoryPage'
+
+const queryClient = new QueryClient()
+
+export default function App() {
+  return (
+    <QueryClientProvider client={queryClient}>
+      <BrowserRouter>
+        <div className="min-h-screen bg-slate-900 text-slate-50">
+          <header className="bg-slate-800 border-b border-slate-700 px-4 py-3 flex items-center gap-3 sticky top-0 z-20">
+            <div className="w-8 h-8 rounded bg-emerald-500 flex items-center justify-center text-slate-900 font-bold text-lg">E</div>
+            <h1 className="text-lg font-semibold">Extrudex</h1>
+          </header>
+          <main className="p-4">
+            <Routes>
+              <Route path="/" element={<Dashboard />} />
+              <Route path="/inventory" element={<InventoryPage />} />
+            </Routes>
+          </main>
+        </div>
+      </BrowserRouter>
+    </QueryClientProvider>
+  )
+}

frontend/src/app/app.config.ts

@@ -1,13 +0,0 @@
-import { ApplicationConfig, provideBrowserGlobalErrorListeners } from '@angular/core';
-import { provideRouter } from '@angular/router';
-import { provideHttpClient } from '@angular/common/http';
-
-import { routes } from './app.routes';
-
-export const appConfig: ApplicationConfig = {
-  providers: [
-    provideBrowserGlobalErrorListeners(),
-    provideRouter(routes),
-    provideHttpClient(),
-  ]
-};

frontend/src/app/app.html

@@ -1,13 +0,0 @@
-<!-- Extrudex — Homepage (Main Hub) -->
-<main class="main-content">
-  <h1 class="sr-only">Extrudex Dashboard</h1>
-
-  <!-- Status Summary Bar — fleet-wide health at a glance -->
-  <app-dashboard-summary></app-dashboard-summary>
-
-  <!-- Inventory Summary — filament metrics at a glance -->
-  <app-inventory-summary></app-inventory-summary>
-
-  <!-- Filament Inventory — routed view -->
-  <router-outlet />
-</main>

frontend/src/app/app.routes.ts

@@ -1,9 +0,0 @@
-import { Routes } from '@angular/router';
-import { FilamentTableComponent } from './components/filament-table/filament-table.component';
-
-export const routes: Routes = [
-  {
-    path: '',
-    component: FilamentTableComponent,
-  },
-];

frontend/src/app/app.scss

@@ -1,27 +0,0 @@
-:host {
-  display: block;
-  min-height: 100vh;
-  background: #1a1a2e;
-  color: #e0e0e0;
-  font-family: 'Inter', 'Segoe UI', Roboto, sans-serif;
-}
-
-.main-content {
-  padding: 16px;
-
-  @media (min-width: 800px) {
-    padding: 24px;
-  }
-}
-
-.sr-only {
-  position: absolute;
-  width: 1px;
-  height: 1px;
-  padding: 0;
-  margin: -1px;
-  overflow: hidden;
-  clip: rect(0, 0, 0, 0);
-  white-space: nowrap;
-  border: 0;
-}

frontend/src/app/app.spec.ts

@@ -1,23 +0,0 @@
-import { TestBed } from '@angular/core/testing';
-import { App } from './app';
-
-describe('App', () => {
-  beforeEach(async () => {
-    await TestBed.configureTestingModule({
-      imports: [App],
-    }).compileComponents();
-  });
-
-  it('should create the app', () => {
-    const fixture = TestBed.createComponent(App);
-    const app = fixture.componentInstance;
-    expect(app).toBeTruthy();
-  });
-
-  it('should render title', async () => {
-    const fixture = TestBed.createComponent(App);
-    await fixture.whenStable();
-    const compiled = fixture.nativeElement as HTMLElement;
-    expect(compiled.querySelector('h1')?.textContent).toContain('Extrudex Dashboard');
-  });
-});

frontend/src/app/app.ts

@@ -1,29 +0,0 @@
-import { Component, ViewChild } from '@angular/core';
-import { RouterOutlet } from '@angular/router';
-import { DashboardSummaryComponent } from './components/dashboard-summary/dashboard-summary.component';
-import { InventorySummaryComponent } from './components/inventory-summary/inventory-summary.component';
-import { AgentSummary, SystemHealth } from './models/agent.model';
-
-@Component({
-  selector: 'app-root',
-  imports: [RouterOutlet, DashboardSummaryComponent, InventorySummaryComponent],
-  templateUrl: './app.html',
-  styleUrl: './app.scss'
-})
-export class App {
-  @ViewChild(DashboardSummaryComponent) summaryComponent!: DashboardSummaryComponent;
-
-  /** Sample data for development — will be replaced by real service data */
-  readonly sampleSummary: AgentSummary = {
-    total: 7,
-    active: 4,
-    idle: 1,
-    thinking: 1,
-    error: 1,
-  };
-
-  readonly sampleHealth: SystemHealth = {
-    connected: true,
-    status: 'healthy',
-  };
-}

frontend/src/app/components/dashboard-summary/dashboard-summary.component.html

@@ -1,63 +0,0 @@
-<!-- Dashboard Summary Bar — Fleet-wide health at a glance -->
-<section class="dashboard-summary" role="status" aria-label="Dashboard summary">
-
-  <!-- System Health Indicator -->
-  <div class="summary-item health-indicator"
-       [class.healthy]="health().status === 'healthy'"
-       [class.degraded]="isDegraded()"
-       [class.down]="isDown()"
-       [matTooltip]="statusLabel()"
-       matTooltipPosition="below">
-    <span class="connection-dot" [class.connected]="health().connected"></span>
-    <span class="health-label">{{ statusLabel() }}</span>
-  </div>
-
-  <!-- Total Active Agents -->
-  <div class="summary-item" matTooltip="Total active agents" matTooltipPosition="below">
-    <mat-icon aria-hidden="true">smart_toy</mat-icon>
-    <span class="metric-value">{{ summary().active }} / {{ summary().total }}</span>
-    <span class="metric-label">Active</span>
-  </div>
-
-  <!-- Status Breakdown -->
-  <div class="summary-item status-breakdown">
-    <mat-chip-set aria-label="Agent status breakdown">
-      <mat-chip
-        class="status-chip chip-active"
-        [class.has-count]="summary().active > 0"
-        matTooltip="Active agents">
-        <mat-icon matChipStart>check_circle</mat-icon>
-        <span class="chip-count">{{ summary().active }}</span>
-        <span class="chip-label">Active</span>
-      </mat-chip>
-
-      <mat-chip
-        class="status-chip chip-idle"
-        [class.has-count]="summary().idle > 0"
-        matTooltip="Idle agents">
-        <mat-icon matChipStart>pause_circle</mat-icon>
-        <span class="chip-count">{{ summary().idle }}</span>
-        <span class="chip-label">Idle</span>
-      </mat-chip>
-
-      <mat-chip
-        class="status-chip chip-thinking"
-        [class.has-count]="summary().thinking > 0"
-        matTooltip="Thinking agents">
-        <mat-icon matChipStart>psychology</mat-icon>
-        <span class="chip-count">{{ summary().thinking }}</span>
-        <span class="chip-label">Thinking</span>
-      </mat-chip>
-
-      <mat-chip
-        class="status-chip chip-error"
-        [class.has-count]="hasErrors()"
-        matTooltip="Agents in error">
-        <mat-icon matChipStart>error</mat-icon>
-        <span class="chip-count">{{ summary().error }}</span>
-        <span class="chip-label">Error</span>
-      </mat-chip>
-    </mat-chip-set>
-  </div>
-
-</section>

frontend/src/app/components/dashboard-summary/dashboard-summary.component.scss

@@ -1,174 +0,0 @@
-/**
- * Dashboard Summary Component Styles
- * Touch-optimized for kiosk (Raspberry Pi 5) and mobile PWA
- * Uses Angular Material utility classes where possible
- */
-
-// Touch-optimized sizing
-$touch-target-min: 48px;
-$kiosk-font-primary: 20px;
-$mobile-font-primary: 16px;
-$spacing-unit: 8px;
-
-// Status colors — high contrast for workshop/bright environments
-$color-active: #4ade70;    // Green — printing/active
-$color-idle: #94a3b8;      // Gray — idle/offline
-$color-thinking: #60a5fa;  // Blue — thinking/processing
-$color-error: #f87171;     // Red — error/failed
-$color-connected: #4ade70; // Green — SignalR connected
-$color-disconnected: #f87171; // Red — disconnected
-
-.dashboard-summary {
-  display: flex;
-  align-items: center;
-  gap: $spacing-unit * 2;
-  padding: $spacing-unit * 2;
-  overflow-x: auto;
-  -webkit-overflow-scrolling: touch;
-
-  // Responsive: on mobile, allow horizontal scroll
-  @media (max-width: 480px) {
-    padding: $spacing-unit;
-    gap: $spacing-unit;
-  }
-}
-
-.summary-item {
-  display: flex;
-  align-items: center;
-  gap: $spacing-unit;
-  min-height: $touch-target-min;
-  white-space: nowrap;
-
-  .metric-value {
-    font-size: $kiosk-font-primary;
-    font-weight: 600;
-    line-height: 1.2;
-
-    @media (max-width: 480px) {
-      font-size: $mobile-font-primary;
-    }
-  }
-
-  .metric-label {
-    font-size: 12px;
-    color: rgba(255, 255, 255, 0.7);
-    text-transform: uppercase;
-    letter-spacing: 0.05em;
-
-    @media (max-width: 480px) {
-      font-size: 10px;
-    }
-  }
-}
-
-// Health indicator
-.health-indicator {
-  padding: $spacing-unit $spacing-unit * 2;
-  border-radius: 24px;
-  transition: background-color 0.3s ease;
-
-  &.healthy {
-    background-color: rgba($color-active, 0.15);
-  }
-
-  &.degraded {
-    background-color: rgba($color-thinking, 0.15);
-  }
-
-  &.down {
-    background-color: rgba($color-error, 0.15);
-  }
-
-  .connection-dot {
-    width: 12px;
-    height: 12px;
-    border-radius: 50%;
-    display: inline-block;
-    transition: background-color 0.3s ease;
-
-    &.connected {
-      background-color: $color-connected;
-      box-shadow: 0 0 6px $color-connected;
-    }
-
-    &:not(.connected) {
-      background-color: $color-disconnected;
-      box-shadow: 0 0 6px $color-disconnected;
-    }
-  }
-
-  .health-label {
-    font-size: 14px;
-    font-weight: 500;
-
-    @media (max-width: 480px) {
-      font-size: 12px;
-    }
-  }
-}
-
-// Status breakdown chips
-.status-breakdown {
-  flex-shrink: 0;
-}
-
-.status-chip {
-  min-height: $touch-target-min !important;
-  font-size: 14px !important;
-
-  @media (max-width: 480px) {
-    min-height: 40px !important;
-    font-size: 12px !important;
-    padding: 0 8px !important;
-  }
-
-  .chip-count {
-    font-weight: 700;
-    margin: 0 4px;
-  }
-
-  .chip-label {
-    font-size: 12px;
-    opacity: 0.8;
-  }
-
-  mat-icon {
-    font-size: 18px !important;
-    width: 18px !important;
-    height: 18px !important;
-  }
-}
-
-// Status chip color variants
-.chip-active {
-  --mdc-chip-outline-color: #{$color-active};
-
-  &.has-count {
-    background-color: rgba($color-active, 0.15) !important;
-  }
-}
-
-.chip-idle {
-  --mdc-chip-outline-color: #{$color-idle};
-
-  &.has-count {
-    background-color: rgba($color-idle, 0.15) !important;
-  }
-}
-
-.chip-thinking {
-  --mdc-chip-outline-color: #{$color-thinking};
-
-  &.has-count {
-    background-color: rgba($color-thinking, 0.15) !important;
-  }
-}
-
-.chip-error {
-  --mdc-chip-outline-color: #{$color-error};
-
-  &.has-count {
-    background-color: rgba($color-error, 0.2) !important;
-  }
-}

frontend/src/app/components/dashboard-summary/dashboard-summary.component.spec.ts

@@ -1,103 +0,0 @@
-import { ComponentFixture, TestBed } from '@angular/core/testing';
-import { DashboardSummaryComponent } from './dashboard-summary.component';
-import { AgentSummary, SystemHealth } from '../../models/agent.model';
-
-describe('DashboardSummaryComponent', () => {
-  let component: DashboardSummaryComponent;
-  let fixture: ComponentFixture<DashboardSummaryComponent>;
-
-  const mockSummary: AgentSummary = {
-    total: 7,
-    active: 4,
-    idle: 1,
-    thinking: 1,
-    error: 1,
-  };
-
-  const mockHealthy: SystemHealth = {
-    connected: true,
-    status: 'healthy',
-  };
-
-  beforeEach(async () => {
-    await TestBed.configureTestingModule({
-      imports: [DashboardSummaryComponent],
-    }).compileComponents();
-
-    fixture = TestBed.createComponent(DashboardSummaryComponent);
-    component = fixture.componentInstance;
-  });
-
-  it('should create', () => {
-    expect(component).toBeTruthy();
-  });
-
-  it('should default to zeroed summary', () => {
-    const summary = component.summary();
-    expect(summary.total).toBe(0);
-    expect(summary.active).toBe(0);
-    expect(summary.idle).toBe(0);
-    expect(summary.thinking).toBe(0);
-    expect(summary.error).toBe(0);
-  });
-
-  it('should default to disconnected/down health', () => {
-    const health = component.health();
-    expect(health.connected).toBe(false);
-    expect(health.status).toBe('down');
-  });
-
-  it('should update summary data', () => {
-    component.updateSummary(mockSummary);
-    expect(component.summary()).toEqual(mockSummary);
-  });
-
-  it('should update health data', () => {
-    component.updateHealth(mockHealthy);
-    expect(component.health()).toEqual(mockHealthy);
-  });
-
-  it('should compute hasErrors correctly', () => {
-    expect(component.hasErrors()).toBe(false);
-    component.updateSummary({ ...mockSummary, error: 2 });
-    expect(component.hasErrors()).toBe(true);
-  });
-
-  it('should compute connectionColor correctly', () => {
-    expect(component.connectionColor()).toBe('disconnected');
-    component.updateHealth({ connected: true, status: 'healthy' });
-    expect(component.connectionColor()).toBe('connected');
-  });
-
-  it('should compute statusLabel for each state', () => {
-    component.updateHealth({ connected: true, status: 'healthy' });
-    expect(component.statusLabel()).toBe('All Systems Go');
-
-    component.updateHealth({ connected: true, status: 'degraded' });
-    expect(component.statusLabel()).toBe('Degraded');
-
-    component.updateHealth({ connected: false, status: 'down' });
-    expect(component.statusLabel()).toBe('Offline');
-  });
-
-  it('should render summary values in template', () => {
-    component.updateSummary(mockSummary);
-    component.updateHealth(mockHealthy);
-    fixture.detectChanges();
-
-    const compiled = fixture.nativeElement as HTMLElement;
-    expect(compiled.textContent).toContain('4 / 7');
-    expect(compiled.textContent).toContain('Active');
-    expect(compiled.textContent).toContain('All Systems Go');
-  });
-
-  it('should render status breakdown chips', () => {
-    component.updateSummary(mockSummary);
-    fixture.detectChanges();
-
-    const compiled = fixture.nativeElement as HTMLElement;
-    expect(compiled.textContent).toContain('4');  // active count
-    expect(compiled.textContent).toContain('1');   // idle count (multiple)
-    expect(compiled.textContent).toContain('Error');
-  });
-});

frontend/src/app/components/dashboard-summary/dashboard-summary.component.ts

@@ -1,80 +0,0 @@
-import { ChangeDetectionStrategy, Component, Input, OnDestroy, signal, computed } from '@angular/core';
-import { CommonModule } from '@angular/common';
-import { MatButtonModule } from '@angular/material/button';
-import { MatIconModule } from '@angular/material/icon';
-import { MatChipsModule } from '@angular/material/chips';
-import { MatTooltipModule } from '@angular/material/tooltip';
-import { AgentSummary, SystemHealth } from '../../models/agent.model';
-
-@Component({
-  selector: 'app-dashboard-summary',
-  standalone: true,
-  imports: [
-    CommonModule,
-    MatButtonModule,
-    MatIconModule,
-    MatChipsModule,
-    MatTooltipModule,
-  ],
-  templateUrl: './dashboard-summary.component.html',
-  styleUrls: ['./dashboard-summary.component.scss'],
-  changeDetection: ChangeDetectionStrategy.OnPush,
-})
-export class DashboardSummaryComponent implements OnDestroy {
-  /** Agent summary data — reactive signal, updatable via updateSummary() */
-  readonly summary = signal<AgentSummary>({
-    total: 0,
-    active: 0,
-    idle: 0,
-    thinking: 0,
-    error: 0,
-  });
-
-  /** System health data — reactive signal, updatable via updateHealth() */
-  readonly health = signal<SystemHealth>({
-    connected: false,
-    status: 'down',
-  });
-
-  /** Computed signal: whether there are errors to highlight */
-  readonly hasErrors = computed(() => this.summary().error > 0);
-
-  /** Computed signal: whether system is degraded */
-  readonly isDegraded = computed(() => this.health().status === 'degraded');
-
-  /** Computed signal: whether system is down */
-  readonly isDown = computed(() => this.health().status === 'down');
-
-  /** Computed signal: connection indicator color */
-  readonly connectionColor = computed(() =>
-    this.health().connected ? 'connected' : 'disconnected'
-  );
-
-  /** Computed signal: overall status label */
-  readonly statusLabel = computed(() => {
-    const h = this.health();
-    if (h.status === 'healthy') return 'All Systems Go';
-    if (h.status === 'degraded') return 'Degraded';
-    return 'Offline';
-  });
-
-  /**
-   * Update the agent summary. Called by the parent or a service
-   * when new data arrives (e.g., via SignalR).
-   */
-  updateSummary(data: AgentSummary): void {
-    this.summary.set(data);
-  }
-
-  /**
-   * Update the system health. Called by the parent or a service
-   * when the connection state changes.
-   */
-  updateHealth(data: SystemHealth): void {
-    this.health.set(data);
-  }
-
-  ngOnDestroy(): void {
-    // Cleanup handled by signals — no manual subscription teardown needed
-  }
-}

frontend/src/app/components/filament-dialog/filament-dialog.component.html

@@ -1,225 +0,0 @@
-<!-- Filament Add/Edit Dialog — Angular Material Dialog -->
-<mat-dialog-content class="filament-dialog-content">
-
-  <!-- Dialog Title -->
-  <h2 mat-dialog-title>{{ dialogTitle() }}</h2>
-
-  <!-- Loading state for lookup data -->
-  @if (lookupsLoading()) {
-    <div class="dialog-loading" role="status" aria-label="Loading material options">
-      <mat-spinner diameter="32"></mat-spinner>
-      <p>Loading material options…</p>
-    </div>
-  }
-
-  <!-- Form -->
-  @if (!lookupsLoading()) {
-    <form [formGroup]="form" class="filament-form" (ngSubmit)="save()">
-
-      <!-- Server Error Banner -->
-      @if (serverError()) {
-        <div class="error-banner" role="alert">
-          <mat-icon aria-hidden="true">error</mat-icon>
-          <span>{{ serverError() }}</span>
-        </div>
-      }
-
-      <!-- ── Material Section ──────────────────────────────── -->
-      <div class="form-section">
-        <h3 class="section-title">Material</h3>
-
-        <!-- Base Material -->
-        <mat-form-field appearance="outline" class="form-field full-width">
-          <mat-label>Base Material</mat-label>
-          <mat-select formControlName="materialBaseId" required aria-label="Base material">
-            @for (base of materialBases(); track base.id) {
-              <mat-option [value]="base.id">{{ base.name }}</mat-option>
-            }
-          </mat-select>
-          @if (form.get('materialBaseId')!.hasError('required') && form.get('materialBaseId')!.touched) {
-            <mat-error>Base material is required</mat-error>
-          }
-        </mat-form-field>
-
-        <!-- Finish -->
-        <mat-form-field appearance="outline" class="form-field full-width">
-          <mat-label>Finish</mat-label>
-          <mat-select formControlName="materialFinishId" required aria-label="Material finish">
-            <mat-option [value]="''" disabled>Select a base material first</mat-option>
-            @for (finish of filteredFinishes(); track finish.id) {
-              <mat-option [value]="finish.id">{{ finish.name }}</mat-option>
-            }
-          </mat-select>
-          @if (form.get('materialFinishId')!.hasError('required') && form.get('materialFinishId')!.touched) {
-            <mat-error>Finish is required</mat-error>
-          }
-          @if (filteredFinishes().length === 0 && form.get('materialBaseId')!.value) {
-            <mat-hint>No finishes available for this material</mat-hint>
-          }
-        </mat-form-field>
-
-        <!-- Modifier (optional) -->
-        <mat-form-field appearance="outline" class="form-field full-width">
-          <mat-label>Modifier (optional)</mat-label>
-          <mat-select formControlName="materialModifierId" aria-label="Material modifier">
-            <mat-option [value]="null">None</mat-option>
-            @for (modifier of filteredModifiers(); track modifier.id) {
-              <mat-option [value]="modifier.id">{{ modifier.name }}</mat-option>
-            }
-          </mat-select>
-          @if (filteredModifiers().length === 0 && form.get('materialBaseId')!.value) {
-            <mat-hint>No modifiers available for this material</mat-hint>
-          }
-        </mat-form-field>
-      </div>
-
-      <!-- ── Spool Details Section ──────────────────────────── -->
-      <div class="form-section">
-        <h3 class="section-title">Spool Details</h3>
-
-        <!-- Brand -->
-        <mat-form-field appearance="outline" class="form-field full-width">
-          <mat-label>Brand</mat-label>
-          <input matInput formControlName="brand" required maxlength="200"
-                 placeholder="e.g., Bambu Lab, Polymaker" aria-label="Brand" />
-          @if (form.get('brand')!.hasError('required') && form.get('brand')!.touched) {
-            <mat-error>Brand is required</mat-error>
-          }
-        </mat-form-field>
-
-        <!-- Serial -->
-        <mat-form-field appearance="outline" class="form-field full-width">
-          <mat-label>Serial Number</mat-label>
-          <input matInput formControlName="spoolSerial" required maxlength="200"
-                 placeholder="e.g., SN-001" aria-label="Serial number" />
-          @if (form.get('spoolSerial')!.hasError('required') && form.get('spoolSerial')!.touched) {
-            <mat-error>Serial number is required</mat-error>
-          }
-        </mat-form-field>
-
-        <!-- Color Name + Color Hex (side by side) -->
-        <div class="form-row">
-          <mat-form-field appearance="outline" class="form-field">
-            <mat-label>Color Name</mat-label>
-            <input matInput formControlName="colorName" required maxlength="200"
-                   placeholder="e.g., Fire Engine Red" aria-label="Color name" />
-            @if (form.get('colorName')!.hasError('required') && form.get('colorName')!.touched) {
-              <mat-error>Color name is required</mat-error>
-            }
-          </mat-form-field>
-
-          <mat-form-field appearance="outline" class="form-field color-hex-field">
-            <mat-label>Color Hex</mat-label>
-            <input matInput formControlName="colorHex" required
-                   placeholder="#FF0000" maxlength="7" aria-label="Color hex code" />
-            <span matTextSuffix class="color-preview">
-              <span class="color-swatch-mini" [style.background-color]="form.get('colorHex')!.value"></span>
-            </span>
-            @if (form.get('colorHex')!.hasError('required') && form.get('colorHex')!.touched) {
-              <mat-error>Color hex is required</mat-error>
-            }
-            @if (form.get('colorHex')!.hasError('pattern') && form.get('colorHex')!.touched) {
-              <mat-error>Must be #RRGGBB format</mat-error>
-            }
-          </mat-form-field>
-        </div>
-      </div>
-
-      <!-- ── Weight & Dimensions Section ────────────────────── -->
-      <div class="form-section">
-        <h3 class="section-title">Weight &amp; Dimensions</h3>
-
-        <div class="form-row">
-          <!-- Diameter -->
-          <mat-form-field appearance="outline" class="form-field">
-            <mat-label>Diameter (mm)</mat-label>
-            <input matInput type="number" formControlName="filamentDiameterMm" required
-                   min="0.1" max="10" step="0.01" aria-label="Filament diameter in mm" />
-            @if (form.get('filamentDiameterMm')!.hasError('required') && form.get('filamentDiameterMm')!.touched) {
-              <mat-error>Diameter is required</mat-error>
-            }
-          </mat-form-field>
-        </div>
-
-        <div class="form-row">
-          <!-- Total Weight -->
-          <mat-form-field appearance="outline" class="form-field">
-            <mat-label>Total Weight (g)</mat-label>
-            <input matInput type="number" formControlName="weightTotalGrams" required
-                   min="0.01" max="100000" step="1" aria-label="Total spool weight in grams" />
-            <mat-hint>Full spool weight</mat-hint>
-            @if (form.get('weightTotalGrams')!.hasError('required') && form.get('weightTotalGrams')!.touched) {
-              <mat-error>Total weight is required</mat-error>
-            }
-          </mat-form-field>
-
-          <!-- Remaining Weight -->
-          <mat-form-field appearance="outline" class="form-field">
-            <mat-label>Remaining Weight (g)</mat-label>
-            <input matInput type="number" formControlName="weightRemainingGrams" required
-                   min="0" max="100000" step="1" aria-label="Remaining weight in grams" />
-            <mat-hint>Current remaining</mat-hint>
-            @if (form.get('weightRemainingGrams')!.hasError('required') && form.get('weightRemainingGrams')!.touched) {
-              <mat-error>Remaining weight is required</mat-error>
-            }
-            @if (form.get('weightRemainingGrams')!.hasError('exceedsTotal')) {
-              <mat-error>Cannot exceed total weight</mat-error>
-            }
-          </mat-form-field>
-        </div>
-      </div>
-
-      <!-- ── Purchase & Status Section ──────────────────────── -->
-      <div class="form-section">
-        <h3 class="section-title">Purchase &amp; Status</h3>
-
-        <div class="form-row">
-          <!-- Purchase Price -->
-          <mat-form-field appearance="outline" class="form-field">
-            <mat-label>Price</mat-label>
-            <input matInput type="number" formControlName="purchasePrice"
-                   min="0" max="1000000" step="0.01"
-                   placeholder="e.g., 25.00" aria-label="Purchase price" />
-            <span matTextSuffix>$</span>
-            @if (form.get('purchasePrice')!.hasError('min') && form.get('purchasePrice')!.touched) {
-              <mat-error>Price must be non-negative</mat-error>
-            }
-          </mat-form-field>
-
-          <!-- Purchase Date -->
-          <mat-form-field appearance="outline" class="form-field">
-            <mat-label>Purchase Date</mat-label>
-            <input matInput [matDatepicker]="picker" formControlName="purchaseDate"
-                   aria-label="Purchase date" />
-            <mat-datepicker-toggle matIconSuffix [for]="picker"></mat-datepicker-toggle>
-            <mat-datepicker #picker></mat-datepicker>
-          </mat-form-field>
-        </div>
-
-        <!-- Active Status -->
-        <div class="checkbox-row">
-          <mat-checkbox formControlName="isActive" aria-label="Active status">
-            Spool is active and available for use
-          </mat-checkbox>
-        </div>
-      </div>
-
-    </form>
-  }
-
-</mat-dialog-content>
-
-<!-- Dialog Actions -->
-<mat-dialog-actions align="end">
-  <button mat-button type="button" (click)="cancel()" [disabled]="saving()"
-          aria-label="Cancel">
-    Cancel
-  </button>
-  <button mat-raised-button color="primary" type="button" (click)="save()"
-          [disabled]="saving() || form.invalid" aria-label="Save filament">
-    @if (saving()) {
-      <mat-spinner diameter="20" class="btn-spinner"></mat-spinner>
-    }
-    {{ isEditMode() ? 'Save Changes' : 'Add Filament' }}
-  </button>
-</mat-dialog-actions>

frontend/src/app/components/filament-dialog/filament-dialog.component.scss

@@ -1,175 +0,0 @@
-/**
- * Filament Dialog Styles
- * Touch-optimized for kiosk (Raspberry Pi 5) and mobile PWA
- */
-
-$touch-target-min: 48px;
-$spacing-unit: 8px;
-$color-error: #ef4444;
-
-// ── Dialog Layout ──────────────────────────────────────────
-
-.filament-dialog-content {
-  overflow-y: auto;
-  max-height: 70vh;
-  padding: 0 $spacing-unit * 2;
-
-  @media (max-width: 480px) {
-    padding: 0 $spacing-unit;
-  }
-}
-
-[mat-dialog-title] {
-  margin: 0 0 $spacing-unit * 2 0;
-  padding: $spacing-unit * 2 0 0 0;
-  font-size: 20px;
-  font-weight: 600;
-}
-
-// ── Loading State ──────────────────────────────────────────
-
-.dialog-loading {
-  display: flex;
-  flex-direction: column;
-  align-items: center;
-  justify-content: center;
-  padding: 48px $spacing-unit * 2;
-  color: var(--mat-sys-on-surface-variant);
-
-  p {
-    margin-top: $spacing-unit * 2;
-    font-size: 14px;
-  }
-}
-
-// ── Error Banner ───────────────────────────────────────────
-
-.error-banner {
-  display: flex;
-  align-items: center;
-  gap: $spacing-unit;
-  padding: $spacing-unit * 1.5 $spacing-unit * 2;
-  border-radius: 8px;
-  margin-bottom: $spacing-unit * 2;
-  background-color: rgba($color-error, 0.12);
-  color: $color-error;
-  border: 1px solid rgba($color-error, 0.3);
-  font-size: 14px;
-  font-weight: 500;
-
-  mat-icon {
-    font-size: 20px !important;
-    width: 20px !important;
-    height: 20px !important;
-  }
-}
-
-// ── Form Sections ──────────────────────────────────────────
-
-.form-section {
-  margin-bottom: $spacing-unit * 3;
-
-  .section-title {
-    font-size: 14px;
-    font-weight: 600;
-    text-transform: uppercase;
-    letter-spacing: 0.04em;
-    color: var(--mat-sys-on-surface-variant);
-    margin: 0 0 $spacing-unit * 1.5 0;
-    padding-bottom: $spacing-unit * 0.5;
-    border-bottom: 1px solid var(--mat-sys-outline-variant);
-  }
-}
-
-.filament-form {
-  display: flex;
-  flex-direction: column;
-  gap: $spacing-unit;
-}
-
-// ── Form Fields ────────────────────────────────────────────
-
-.form-field {
-  width: 100%;
-
-  // Touch target sizing
-  .mat-mdc-form-field-subscript-wrapper {
-    min-height: 20px;
-  }
-}
-
-.form-row {
-  display: flex;
-  gap: $spacing-unit * 2;
-  width: 100%;
-
-  .form-field {
-    flex: 1;
-  }
-
-  @media (max-width: 480px) {
-    flex-direction: column;
-    gap: 0;
-  }
-}
-
-// ── Color Hex Preview ──────────────────────────────────────
-
-.color-hex-field {
-  max-width: 180px;
-
-  @media (max-width: 480px) {
-    max-width: 100%;
-  }
-}
-
-.color-preview {
-  display: inline-flex;
-  align-items: center;
-  margin-left: 4px;
-}
-
-.color-swatch-mini {
-  display: inline-block;
-  width: 20px;
-  height: 20px;
-  border-radius: 4px;
-  border: 1px solid rgba(0, 0, 0, 0.12);
-  vertical-align: middle;
-}
-
-// ── Checkbox Row ───────────────────────────────────────────
-
-.checkbox-row {
-  display: flex;
-  align-items: center;
-  padding: $spacing-unit 0;
-
-  mat-checkbox {
-    min-height: $touch-target-min;
-    display: flex;
-    align-items: center;
-  }
-}
-
-// ── Save Button Spinner ────────────────────────────────────
-
-mat-dialog-actions {
-  padding: $spacing-unit $spacing-unit * 2 $spacing-unit * 2;
-  gap: $spacing-unit;
-
-  button {
-    min-height: $touch-target-min;
-    min-width: 100px;
-  }
-}
-
-.btn-spinner {
-  display: inline-block;
-  margin-right: $spacing-unit;
-  vertical-align: middle;
-
-  circle {
-    stroke: currentColor;
-  }
-}

frontend/src/app/components/filament-dialog/filament-dialog.component.ts

@@ -1,277 +0,0 @@
-import {
-  ChangeDetectionStrategy,
-  Component,
-  inject,
-  signal,
-  computed,
-} from '@angular/core';
-import { CommonModule } from '@angular/common';
-import { FormsModule, ReactiveFormsModule, FormBuilder, FormGroup, Validators } from '@angular/forms';
-import { MatDialogRef, MAT_DIALOG_DATA, MatDialogModule } from '@angular/material/dialog';
-import { MatFormFieldModule } from '@angular/material/form-field';
-import { MatInputModule } from '@angular/material/input';
-import { MatSelectModule } from '@angular/material/select';
-import { MatDatepickerModule } from '@angular/material/datepicker';
-import { MatNativeDateModule } from '@angular/material/core';
-import { MatCheckboxModule } from '@angular/material/checkbox';
-import { MatButtonModule } from '@angular/material/button';
-import { MatIconModule } from '@angular/material/icon';
-import { MatProgressSpinnerModule } from '@angular/material/progress-spinner';
-import { MatTooltipModule } from '@angular/material/tooltip';
-
-import { Filament } from '../../models/filament.model';
-import {
-  MaterialBase,
-  MaterialFinish,
-  MaterialModifier,
-} from '../../models/material.model';
-import {
-  FilamentService,
-  CreateFilamentRequest,
-  UpdateFilamentRequest,
-} from '../../services/filament.service';
-
-/** Data passed into the dialog from the opener. */
-export interface FilamentDialogData {
-  /** If provided, the dialog opens in edit mode with pre-populated fields. */
-  filament?: Filament;
-}
-
-@Component({
-  selector: 'app-filament-dialog',
-  standalone: true,
-  imports: [
-    CommonModule,
-    FormsModule,
-    ReactiveFormsModule,
-    MatDialogModule,
-    MatFormFieldModule,
-    MatInputModule,
-    MatSelectModule,
-    MatDatepickerModule,
-    MatNativeDateModule,
-    MatCheckboxModule,
-    MatButtonModule,
-    MatIconModule,
-    MatProgressSpinnerModule,
-    MatTooltipModule,
-  ],
-  templateUrl: './filament-dialog.component.html',
-  styleUrl: './filament-dialog.component.scss',
-  changeDetection: ChangeDetectionStrategy.OnPush,
-})
-export class FilamentDialogComponent {
-  private readonly dialogRef = inject(MatDialogRef<FilamentDialogComponent>);
-  private readonly data = inject<FilamentDialogData>(MAT_DIALOG_DATA);
-  private readonly fb = inject(FormBuilder);
-  private readonly filamentService = inject(FilamentService);
-
-  /** Whether this dialog is in edit mode (has existing filament data). */
-  readonly isEditMode = computed(() => !!this.data.filament);
-
-  /** Dialog title based on mode. */
-  readonly dialogTitle = computed(() =>
-    this.isEditMode() ? 'Edit Filament' : 'Add Filament'
-  );
-
-  // ── Lookup data signals ──────────────────────────────────
-
-  /** All material bases for the base material dropdown. */
-  readonly materialBases = signal<MaterialBase[]>([]);
-
-  /** Material finishes filtered by selected base material. */
-  readonly filteredFinishes = signal<MaterialFinish[]>([]);
-
-  /** Material modifiers filtered by selected base material. */
-  readonly filteredModifiers = signal<MaterialModifier[]>([]);
-
-  /** Whether material lookups are loading. */
-  readonly lookupsLoading = signal(true);
-
-  /** Whether the save operation is in progress. */
-  readonly saving = signal(false);
-
-  /** Server error message, if any. */
-  readonly serverError = signal<string | null>(null);
-
-  // ── Form ─────────────────────────────────────────────────
-
-  readonly form: FormGroup = this.fb.group({
-    materialBaseId: ['', Validators.required],
-    materialFinishId: ['', Validators.required],
-    materialModifierId: [null],
-    brand: ['', [Validators.required, Validators.maxLength(200)]],
-    colorName: ['', [Validators.required, Validators.maxLength(200)]],
-    colorHex: ['#000000', [Validators.required, Validators.pattern(/^#[0-9A-Fa-f]{6}$/)]],
-    weightTotalGrams: [1000, [Validators.required, Validators.min(0.01), Validators.max(100000)]],
-    weightRemainingGrams: [1000, [Validators.required, Validators.min(0), Validators.max(100000)]],
-    filamentDiameterMm: [1.75, [Validators.required, Validators.min(0.1), Validators.max(10)]],
-    spoolSerial: ['', [Validators.required, Validators.maxLength(200)]],
-    purchasePrice: [null, [Validators.min(0), Validators.max(1000000)]],
-    purchaseDate: [null],
-    isActive: [true],
-  });
-
-  constructor() {
-    this.loadLookups();
-    this.patchFormIfEditing();
-    this.setupCascadingFilters();
-  }
-
-  // ── Data loading ─────────────────────────────────────────
-
-  /** Load material bases, finishes, and modifiers for dropdowns. */
-  private loadLookups(): void {
-    this.lookupsLoading.set(true);
-    this.filamentService.getMaterialBases().subscribe({
-      next: (bases) => {
-        this.materialBases.set(bases);
-        this.lookupsLoading.set(false);
-      },
-      error: () => {
-        this.lookupsLoading.set(false);
-        this.serverError.set('Failed to load material options. Please try again.');
-      },
-    });
-  }
-
-  /** Pre-populate form fields when editing an existing filament. */
-  private patchFormIfEditing(): void {
-    if (this.data.filament) {
-      const f = this.data.filament;
-      this.form.patchValue({
-        materialBaseId: f.materialBaseId,
-        materialFinishId: f.materialFinishId,
-        materialModifierId: f.materialModifierId,
-        brand: f.brand,
-        colorName: f.colorName,
-        colorHex: f.colorHex,
-        weightTotalGrams: f.weightTotalGrams,
-        weightRemainingGrams: f.weightRemainingGrams,
-        filamentDiameterMm: f.filamentDiameterMm,
-        spoolSerial: f.spoolSerial,
-        purchasePrice: f.purchasePrice,
-        purchaseDate: f.purchaseDate ? new Date(f.purchaseDate) : null,
-        isActive: f.isActive,
-      });
-    }
-  }
-
-  /** Set up cascading filter: when base material changes, reload finishes & modifiers. */
-  private setupCascadingFilters(): void {
-    this.form.get('materialBaseId')!.valueChanges.subscribe((baseId: string | null) => {
-      // Clear dependent selections when base changes
-      this.form.get('materialFinishId')!.setValue('');
-      this.form.get('materialModifierId')!.setValue(null);
-      this.filteredFinishes.set([]);
-      this.filteredModifiers.set([]);
-
-      if (!baseId) return;
-
-      this.filamentService.getMaterialFinishes(baseId).subscribe({
-        next: (finishes) => this.filteredFinishes.set(finishes),
-        error: () => this.filteredFinishes.set([]),
-      });
-
-      this.filamentService.getMaterialModifiers(baseId).subscribe({
-        next: (modifiers) => this.filteredModifiers.set(modifiers),
-        error: () => this.filteredModifiers.set([]),
-      });
-    });
-
-    // If editing, trigger the cascading load for the pre-selected base
-    if (this.data.filament) {
-      const baseId = this.data.filament.materialBaseId;
-      // We need to load finishes and modifiers for the pre-selected base
-      // but also re-select the original finish and modifier after loading
-      this.filamentService.getMaterialFinishes(baseId).subscribe({
-        next: (finishes) => {
-          this.filteredFinishes.set(finishes);
-          // Re-patch finish after load
-          this.form.get('materialFinishId')!.setValue(this.data.filament!.materialFinishId);
-        },
-      });
-      this.filamentService.getMaterialModifiers(baseId).subscribe({
-        next: (modifiers) => {
-          this.filteredModifiers.set(modifiers);
-          // Re-patch modifier after load
-          this.form.get('materialModifierId')!.setValue(this.data.filament!.materialModifierId);
-        },
-      });
-    }
-  }
-
-  // ── Actions ──────────────────────────────────────────────
-
-  /** Cancel and close the dialog without saving. */
-  cancel(): void {
-    this.dialogRef.close(false);
-  }
-
-  /** Submit the form — creates or updates the filament. */
-  save(): void {
-    if (this.form.invalid) {
-      this.form.markAllAsTouched();
-      return;
-    }
-
-    // Cross-field validation: remaining weight must not exceed total weight
-    const total = this.form.value.weightTotalGrams;
-    const remaining = this.form.value.weightRemainingGrams;
-    if (remaining > total) {
-      this.form.get('weightRemainingGrams')!.setErrors({ exceedsTotal: true });
-      return;
-    }
-
-    this.saving.set(true);
-    this.serverError.set(null);
-
-    const formValue = this.form.value;
-    const request: CreateFilamentRequest | UpdateFilamentRequest = {
-      materialBaseId: formValue.materialBaseId,
-      materialFinishId: formValue.materialFinishId,
-      materialModifierId: formValue.materialModifierId || null,
-      brand: formValue.brand.trim(),
-      colorName: formValue.colorName.trim(),
-      colorHex: formValue.colorHex,
-      weightTotalGrams: formValue.weightTotalGrams,
-      weightRemainingGrams: formValue.weightRemainingGrams,
-      filamentDiameterMm: formValue.filamentDiameterMm,
-      spoolSerial: formValue.spoolSerial.trim(),
-      purchasePrice: formValue.purchasePrice ?? null,
-      purchaseDate: formValue.purchaseDate
-        ? new Date(formValue.purchaseDate).toISOString()
-        : null,
-      isActive: formValue.isActive,
-    };
-
-    if (this.isEditMode()) {
-      const id = this.data.filament!.id;
-      this.filamentService.updateFilament(id, request).subscribe({
-        next: (updated) => {
-          this.saving.set(false);
-          this.dialogRef.close(true);
-        },
-        error: (err) => {
-          this.saving.set(false);
-          this.serverError.set(
-            err?.error?.error || err?.message || 'Failed to update filament. Please try again.'
-          );
-        },
-      });
-    } else {
-      this.filamentService.createFilament(request).subscribe({
-        next: (created) => {
-          this.saving.set(false);
-          this.dialogRef.close(true);
-        },
-        error: (err) => {
-          this.saving.set(false);
-          this.serverError.set(
-            err?.error?.error || err?.message || 'Failed to create filament. Please try again.'
-          );
-        },
-      });
-    }
-  }
-}

frontend/src/app/components/filament-filter/filament-filter.component.html

@@ -1,76 +0,0 @@
-<!-- Filament Filter Bar — material type, color search, low stock, active-only -->
-<div class="filament-filter-bar" role="search" aria-label="Filter filament inventory">
-
-  <!-- Material Type Multi-Select -->
-  <mat-form-field appearance="outline" class="filter-field material-filter">
-    <mat-label>Material</mat-label>
-    <mat-select multiple
-                [value]="selectedMaterials()"
-                (selectionChange)="onMaterialChange($event.value)"
-                aria-label="Filter by material type">
-      @for (material of materialOptions(); track material) {
-        <mat-option [value]="material">{{ material }}</mat-option>
-      }
-    </mat-select>
-    @if (selectedMaterials().length > 0) {
-      <mat-chip-set class="selected-chips" matSuffix>
-        @for (mat of selectedMaterials(); track mat) {
-          <mat-chip (removed)="removeMaterial(mat)"
-                    class="filter-chip">
-            <span>{{ mat }}</span>
-            <mat-icon matChipRemove>cancel</mat-icon>
-          </mat-chip>
-        }
-      </mat-chip-set>
-    }
-  </mat-form-field>
-
-  <!-- Color Search -->
-  <mat-form-field appearance="outline" class="filter-field color-filter">
-    <mat-label>Color</mat-label>
-    <input matInput
-           type="text"
-           [value]="colorSearch()"
-           (input)="onColorSearchChange($any($event.target).value)"
-           placeholder="Search color..."
-           aria-label="Filter by color name" />
-    @if (colorSearch().trim()) {
-      <mat-icon matSuffix class="filter-active-icon">filter_list</mat-icon>
-    }
-  </mat-form-field>
-
-  <!-- Low Stock Toggle -->
-  <mat-checkbox [checked]="lowStockOnly()"
-                (change)="onLowStockToggle($event.checked)"
-                class="filter-checkbox"
-                aria-label="Show low stock only"
-                matTooltip="Show only spools at 25% or less remaining"
-                matTooltipPosition="below">
-    <mat-icon class="checkbox-icon" [class.active]="lowStockOnly()">warning</mat-icon>
-    Low Stock
-  </mat-checkbox>
-
-  <!-- Active Only Toggle -->
-  <mat-checkbox [checked]="activeOnly()"
-                (change)="onActiveOnlyToggle($event.checked)"
-                class="filter-checkbox"
-                aria-label="Show active spools only"
-                matTooltip="Show only spools currently in use"
-                matTooltipPosition="below">
-    <mat-icon class="checkbox-icon" [class.active]="activeOnly()">check_circle</mat-icon>
-    Active Only
-  </mat-checkbox>
-
-  <!-- Clear All Filters -->
-  @if (hasActiveFilters()) {
-    <button mat-button
-            class="clear-filters-btn"
-            (click)="clearAll()"
-            aria-label="Clear all filters"
-            matTooltip="Remove all filters"
-            matTooltipPosition="below">
-      <mat-icon>filter_alt_off</mat-icon>
-      Clear
-    </button>
-  }
-</div>

frontend/src/app/components/filament-filter/filament-filter.component.scss

@@ -1,134 +0,0 @@
-/**
- * Filament Filter Bar Styles
- * Responsive filter layout for kiosk and mobile
- */
-
-$spacing-unit: 8px;
-
-.filament-filter-bar {
-  display: flex;
-  align-items: center;
-  gap: $spacing-unit * 2;
-  flex-wrap: wrap;
-  padding: $spacing-unit * 2 0;
-  margin-bottom: $spacing-unit * 2;
-}
-
-// Form field sizing
-.filter-field {
-  flex: 0 1 auto;
-  min-width: 160px;
-
-  &.material-filter {
-    min-width: 200px;
-  }
-
-  &.color-filter {
-    min-width: 180px;
-  }
-
-  // Reduce vertical spacing inside filter fields
-  .mat-mdc-form-field-subscript-wrapper {
-    display: none; // No hint/error text needed for filters
-  }
-}
-
-// Selected material chips
-.selected-chips {
-  flex-wrap: wrap;
-  gap: 4px;
-}
-
-.filter-chip {
-  font-size: 12px !important;
-  min-height: 24px !important;
-
-  mat-icon {
-    font-size: 14px !important;
-    width: 14px !important;
-    height: 14px !important;
-  }
-}
-
-// Active filter icon
-.filter-active-icon {
-  color: var(--mat-sys-primary);
-  font-size: 18px !important;
-  width: 18px !important;
-  height: 18px !important;
-}
-
-// Checkbox styling
-.filter-checkbox {
-  display: flex;
-  align-items: center;
-  gap: 4px;
-  white-space: nowrap;
-  user-select: none;
-  touch-action: manipulation; // Prevent zoom on double-tap
-
-  .checkbox-icon {
-    font-size: 18px !important;
-    width: 18px !important;
-    height: 18px !important;
-    color: var(--mat-sys-on-surface-variant);
-    transition: color 0.2s ease;
-
-    &.active {
-      color: var(--mat-sys-primary);
-    }
-  }
-}
-
-// Clear filters button
-.clear-filters-btn {
-  display: flex;
-  align-items: center;
-  gap: 4px;
-  font-size: 13px;
-
-  mat-icon {
-    font-size: 18px !important;
-    width: 18px !important;
-    height: 18px !important;
-  }
-}
-
-// Responsive: stack filters vertically on small screens
-@media (max-width: 768px) {
-  .filament-filter-bar {
-    flex-direction: column;
-    align-items: stretch;
-    gap: $spacing-unit;
-  }
-
-  .filter-field {
-    width: 100%;
-    min-width: unset;
-
-    &.material-filter,
-    &.color-filter {
-      min-width: unset;
-    }
-  }
-
-  .filter-checkbox {
-    padding: $spacing-unit 0;
-  }
-
-  .clear-filters-btn {
-    align-self: flex-start;
-  }
-}
-
-// Extra-small screens (phone portrait)
-@media (max-width: 480px) {
-  .filament-filter-bar {
-    padding: $spacing-unit 0;
-    margin-bottom: $spacing-unit;
-  }
-
-  .filter-checkbox {
-    font-size: 13px;
-  }
-}

frontend/src/app/components/filament-filter/filament-filter.component.ts

@@ -1,158 +0,0 @@
-import {
-  ChangeDetectionStrategy,
-  Component,
-  EventEmitter,
-  Input,
-  Output,
-  computed,
-  signal,
-} from '@angular/core';
-import { CommonModule } from '@angular/common';
-import { FormsModule } from '@angular/forms';
-import { MatFormFieldModule } from '@angular/material/form-field';
-import { MatSelectModule } from '@angular/material/select';
-import { MatInputModule } from '@angular/material/input';
-import { MatCheckboxModule } from '@angular/material/checkbox';
-import { MatIconModule } from '@angular/material/icon';
-import { MatChipsModule } from '@angular/material/chips';
-import { MatButtonModule } from '@angular/material/button';
-import { MatTooltipModule } from '@angular/material/tooltip';
-import {
-  Filament,
-  StockLevel,
-  classifyStockLevel,
-} from '../../models/filament.model';
-
-/** Filter state emitted by the filament filter component */
-export interface FilamentFilterState {
-  /** Selected material base names — empty means all */
-  materialBaseNames: string[];
-
-  /** Color search text — empty string means all */
-  colorSearch: string;
-
-  /** Whether to show only low/critical stock */
-  lowStockOnly: boolean;
-
-  /** Whether to show only active spools */
-  activeOnly: boolean;
-}
-
-/**
- * FilamentFilterComponent — Filter bar for the filament inventory list.
- *
- * Provides:
- * - Material type multi-select filter
- * - Color name text search
- * - Low stock toggle (shows only critical/low spools)
- * - Active-only toggle
- * - Clear all filters action
- */
-@Component({
-  selector: 'app-filament-filter',
-  standalone: true,
-  imports: [
-    CommonModule,
-    FormsModule,
-    MatFormFieldModule,
-    MatSelectModule,
-    MatInputModule,
-    MatCheckboxModule,
-    MatIconModule,
-    MatChipsModule,
-    MatButtonModule,
-    MatTooltipModule,
-  ],
-  templateUrl: './filament-filter.component.html',
-  styleUrl: './filament-filter.component.scss',
-  changeDetection: ChangeDetectionStrategy.OnPush,
-})
-export class FilamentFilterComponent {
-  /** Filament data input — used to derive material options */
-  @Input() set filaments(value: Filament[]) {
-    this._filaments.set(value);
-    const materials = [...new Set(value.map((f) => f.materialBaseName))].sort();
-    this.materialOptions.set(materials);
-  }
-  get filaments(): Filament[] {
-    return this._filaments();
-  }
-  private readonly _filaments = signal<Filament[]>([]);
-
-  /** Available material base names derived from filament data */
-  readonly materialOptions = signal<string[]>([]);
-
-  /** Selected material base names */
-  readonly selectedMaterials = signal<string[]>([]);
-
-  /** Color search text */
-  readonly colorSearch = signal('');
-
-  /** Low stock only toggle */
-  readonly lowStockOnly = signal(false);
-
-  /** Active only toggle */
-  readonly activeOnly = signal(false);
-
-  /** Computed: whether any filters are active */
-  readonly hasActiveFilters = computed(
-    () =>
-      this.selectedMaterials().length > 0 ||
-      this.colorSearch().trim().length > 0 ||
-      this.lowStockOnly() ||
-      this.activeOnly()
-  );
-
-  /** Emits the current filter state whenever filters change */
-  @Output() readonly filterChange = new EventEmitter<FilamentFilterState>();
-
-  /** Handle material selection change */
-  onMaterialChange(selected: string[]): void {
-    this.selectedMaterials.set(selected);
-    this.emitFilterState();
-  }
-
-  /** Handle color search input */
-  onColorSearchChange(value: string): void {
-    this.colorSearch.set(value);
-    this.emitFilterState();
-  }
-
-  /** Handle low stock toggle */
-  onLowStockToggle(checked: boolean): void {
-    this.lowStockOnly.set(checked);
-    this.emitFilterState();
-  }
-
-  /** Handle active-only toggle */
-  onActiveOnlyToggle(checked: boolean): void {
-    this.activeOnly.set(checked);
-    this.emitFilterState();
-  }
-
-  /** Remove a single material chip */
-  removeMaterial(material: string): void {
-    const updated = this.selectedMaterials().filter((m) => m !== material);
-    this.selectedMaterials.set(updated);
-    this.emitFilterState();
-  }
-
-  /** Clear all filters */
-  clearAll(): void {
-    this.selectedMaterials.set([]);
-    this.colorSearch.set('');
-    this.lowStockOnly.set(false);
-    this.activeOnly.set(false);
-    this.emitFilterState();
-  }
-
-  /** Emit the current filter state */
-  private emitFilterState(): void {
-    this.filterChange.emit({
-      materialBaseNames: this.selectedMaterials(),
-      colorSearch: this.colorSearch().trim().toLowerCase(),
-      lowStockOnly: this.lowStockOnly(),
-      activeOnly: this.activeOnly(),
-    });
-  }
-}

frontend/src/app/components/filament-table/filament-table.component.html

@@ -1,166 +0,0 @@
-<!-- Filament Inventory Table — with filters and low stock indicators -->
-<div class="filament-table-container" role="region" aria-label="Filament inventory">
-
-  <!-- Filter Bar -->
-  <app-filament-filter
-    [filaments]="allFilaments()"
-    (filterChange)="onFilterChange($event)"
-    aria-label="Filter filament inventory" />
-
-  <!-- Low Stock Alert Banner — shown when critical or low stock spools exist -->
-  @if (criticalCount() > 0) {
-    <div class="alert-banner critical" role="alert">
-      <mat-icon aria-hidden="true">error</mat-icon>
-      <span>{{ criticalCount() }} spool{{ criticalCount() > 1 ? 's' : '' }} critically low (&le;10% remaining)</span>
-    </div>
-  } @else if (lowStockCount() > 0) {
-    <div class="alert-banner low" role="alert">
-      <mat-icon aria-hidden="true">warning</mat-icon>
-      <span>{{ lowStockCount() }} spool{{ lowStockCount() > 1 ? 's' : '' }} running low (&le;25% remaining)</span>
-    </div>
-  }
-
-  <!-- Filament Table -->
-  <table mat-table
-         [dataSource]="filteredFilaments()"
-         matSort
-         (matSortChange)="sortData($event)"
-         class="filament-table"
-         aria-label="Filament inventory table">
-
-    <!-- Color Column -->
-    <ng-container matColumnDef="color">
-      <th mat-header-cell *matHeaderCellDef mat-sort-header="color">Color</th>
-      <td mat-cell *matCellDef="let filament">
-        <span class="color-swatch"
-              [style.background-color]="filament.colorHex"
-              [matTooltip]="filament.colorName"
-              matTooltipPosition="after"
-              [attr.aria-label]="filament.colorName">
-        </span>
-      </td>
-    </ng-container>
-
-    <!-- Material Column -->
-    <ng-container matColumnDef="material">
-      <th mat-header-cell *matHeaderCellDef mat-sort-header="material">Material</th>
-      <td mat-cell *matCellDef="let filament">
-        <span class="material-name">{{ filament.materialBaseName }}</span>
-        @if (filament.materialModifierName) {
-          <span class="material-modifier"> {{ filament.materialModifierName }}</span>
-        }
-      </td>
-    </ng-container>
-
-    <!-- Brand Column -->
-    <ng-container matColumnDef="brand">
-      <th mat-header-cell *matHeaderCellDef mat-sort-header="brand">Brand</th>
-      <td mat-cell *matCellDef="let filament">{{ filament.brand }}</td>
-    </ng-container>
-
-    <!-- Serial Column -->
-    <ng-container matColumnDef="serial">
-      <th mat-header-cell *matHeaderCellDef mat-sort-header="serial">Serial</th>
-      <td mat-cell *matCellDef="let filament" class="serial-cell">{{ filament.spoolSerial }}</td>
-    </ng-container>
-
-    <!-- Remaining Weight Column -->
-    <ng-container matColumnDef="remaining">
-      <th mat-header-cell *matHeaderCellDef mat-sort-header="remaining">Remaining</th>
-      <td mat-cell *matCellDef="let filament">
-        <div class="remaining-cell">
-          <span class="remaining-text">
-            {{ formatWeight(filament.weightRemainingGrams) }} / {{ formatWeight(filament.weightTotalGrams) }}
-          </span>
-          <mat-progress-bar
-            mode="determinate"
-            [value]="getRemainingPercent(filament)"
-            [ngClass]="classifyStockLevel(filament)"
-            [matTooltip]="getRemainingPercent(filament).toFixed(0) + '% remaining'"
-            matTooltipPosition="below">
-          </mat-progress-bar>
-        </div>
-      </td>
-    </ng-container>
-
-    <!-- Cost Column -->
-    <ng-container matColumnDef="cost">
-      <th mat-header-cell *matHeaderCellDef mat-sort-header="cost">Cost</th>
-      <td mat-cell *matCellDef="let filament">
-        <div class="cost-cell">
-          @if (filament.purchasePrice !== null) {
-            <span class="cost-price">{{ formatCurrency(filament.purchasePrice) }}</span>
-            @let cpg = getCostPerGram(filament);
-            @if (cpg !== null) {
-              <span class="cost-per-gram">${{ cpg.toFixed(2) }}/g</span>
-            }
-          } @else {
-            <span class="cost-unknown">&mdash;</span>
-          }
-        </div>
-      </td>
-    </ng-container>
-
-    <!-- Usage Column -->
-    <ng-container matColumnDef="usage">
-      <th mat-header-cell *matHeaderCellDef mat-sort-header="usage">Usage</th>
-      <td mat-cell *matCellDef="let filament">
-        <div class="usage-cell">
-          <span class="usage-grams">{{ formatWeight(getGramsUsed(filament)) }} used</span>
-          <span class="usage-remaining">{{ formatWeight(filament.weightRemainingGrams) }} left</span>
-        </div>
-      </td>
-    </ng-container>
-
-    <!-- Stock Level Indicator Column -->
-    <ng-container matColumnDef="stockLevel">
-      <th mat-header-cell *matHeaderCellDef mat-sort-header="stockLevel">Stock</th>
-      <td mat-cell *matCellDef="let filament">
-        @let level = classifyStockLevel(filament);
-        <mat-chip-set aria-label="Stock level">
-          <mat-chip
-            [ngClass]="level"
-            [matTooltip]="stockLevelLabel(level) + ' — ' + getRemainingPercent(filament).toFixed(0) + '% remaining'"
-            matTooltipPosition="below">
-            <mat-icon matChipStart [ngClass]="level">{{ stockLevelIcon(level) }}</mat-icon>
-            <span>{{ stockLevelLabel(level) }}</span>
-          </mat-chip>
-        </mat-chip-set>
-      </td>
-    </ng-container>
-
-    <!-- Status Column -->
-    <ng-container matColumnDef="status">
-      <th mat-header-cell *matHeaderCellDef mat-sort-header="status">Status</th>
-      <td mat-cell *matCellDef="let filament">
-        <span class="status-badge"
-              [class.active]="filament.isActive"
-              [class.inactive]="!filament.isActive">
-          {{ filament.isActive ? 'Active' : 'Inactive' }}
-        </span>
-      </td>
-    </ng-container>
-
-    <tr mat-header-row *matHeaderRowDef="columns()"></tr>
-    <tr mat-row *matRowDef="let row; columns: columns();"
-        [class.row-critical]="classifyStockLevel(row) === 'critical'"
-        [class.row-low]="classifyStockLevel(row) === 'low'">
-    </tr>
-  </table>
-
-  <!-- Filtered empty state -->
-  @if (filteredFilaments().length === 0 && filaments().length > 0) {
-    <div class="empty-state" role="status">
-      <mat-icon aria-hidden="true">filter_alt_off</mat-icon>
-      <p>No filaments match the current filters</p>
-    </div>
-  }
-
-  <!-- No data empty state -->
-  @if (filaments().length === 0) {
-    <div class="empty-state" role="status">
-      <mat-icon aria-hidden="true">inventory_2</mat-icon>
-      <p>No filament spools found</p>
-    </div>
-  }
-</div>

frontend/src/app/components/filament-table/filament-table.component.scss

@@ -1,301 +0,0 @@
-/**
- * Filament Table Component Styles
- * Touch-optimized for kiosk (Raspberry Pi 5) and mobile PWA
- * Low stock indicators use high-contrast colors for workshop visibility
- */
-
-// Touch-optimized sizing
-$touch-target-min: 48px;
-$spacing-unit: 8px;
-
-// Stock level colors — high contrast, accessible
-$color-critical: #ef4444;   // Red — critically low
-$color-low: #f59e0b;       // Amber — running low
-$color-moderate: #3b82f6;  // Blue — moderate
-$color-healthy: #22c55e;   // Green — healthy/OK
-$color-active: #22c55e;    // Green — active spool
-$color-inactive: #94a3b8;  // Gray — inactive spool
-
-.filament-table-container {
-  width: 100%;
-  overflow-x: auto;
-  -webkit-overflow-scrolling: touch;
-}
-
-// Alert banner for low stock warnings
-.alert-banner {
-  display: flex;
-  align-items: center;
-  gap: $spacing-unit;
-  padding: $spacing-unit * 1.5 $spacing-unit * 2;
-  border-radius: 8px;
-  margin-bottom: $spacing-unit * 2;
-  font-size: 14px;
-  font-weight: 500;
-
-  mat-icon {
-    font-size: 20px !important;
-    width: 20px !important;
-    height: 20px !important;
-  }
-
-  &.critical {
-    background-color: rgba($color-critical, 0.12);
-    color: $color-critical;
-    border: 1px solid rgba($color-critical, 0.3);
-  }
-
-  &.low {
-    background-color: rgba($color-low, 0.12);
-    color: $color-low;
-    border: 1px solid rgba($color-low, 0.3);
-  }
-}
-
-// Table styling
-.filament-table {
-  width: 100%;
-  min-width: 900px;
-
-  th {
-    font-weight: 600;
-    font-size: 13px;
-    text-transform: uppercase;
-    letter-spacing: 0.04em;
-    color: var(--mat-sys-on-surface-variant);
-  }
-
-  td {
-    font-size: 14px;
-    padding: 12px 16px !important;
-    min-height: $touch-target-min;
-
-    @media (max-width: 480px) {
-      padding: 8px 12px !important;
-      font-size: 13px;
-    }
-  }
-
-  // Row highlight for low stock
-  .mat-mdc-row {
-    transition: background-color 0.2s ease;
-  }
-
-  &.row-critical {
-    background-color: rgba($color-critical, 0.06) !important;
-
-    &:hover {
-      background-color: rgba($color-critical, 0.1) !important;
-    }
-  }
-
-  &.row-low {
-    background-color: rgba($color-low, 0.06) !important;
-
-    &:hover {
-      background-color: rgba($color-low, 0.1) !important;
-    }
-  }
-}
-
-// Color swatch
-.color-swatch {
-  display: inline-block;
-  width: 28px;
-  height: 28px;
-  border-radius: 50%;
-  border: 2px solid rgba(0, 0, 0, 0.12);
-  vertical-align: middle;
-  cursor: default;
-
-  @media (max-width: 480px) {
-    width: 24px;
-    height: 24px;
-  }
-}
-
-// Material name
-.material-name {
-  font-weight: 500;
-}
-
-.material-modifier {
-  font-size: 12px;
-  color: var(--mat-sys-on-surface-variant);
-  margin-left: 4px;
-}
-
-// Serial cell — monospace
-.serial-cell {
-  font-family: 'JetBrains Mono', 'Roboto Mono', monospace;
-  font-size: 13px;
-  letter-spacing: 0.02em;
-}
-
-// Cost cell
-.cost-cell {
-  display: flex;
-  flex-direction: column;
-  gap: 2px;
-  min-width: 80px;
-
-  .cost-price {
-    font-weight: 600;
-    color: var(--mat-sys-on-surface);
-  }
-
-  .cost-per-gram {
-    font-size: 11px;
-    color: var(--mat-sys-on-surface-variant);
-    letter-spacing: 0.02em;
-  }
-
-  .cost-unknown {
-    color: var(--mat-sys-on-surface-variant);
-    font-style: italic;
-  }
-}
-
-// Usage cell
-.usage-cell {
-  display: flex;
-  flex-direction: column;
-  gap: 2px;
-  min-width: 100px;
-
-  .usage-grams {
-    font-weight: 500;
-    color: var(--mat-sys-on-surface);
-  }
-
-  .usage-remaining {
-    font-size: 12px;
-    color: var(--mat-sys-on-surface-variant);
-  }
-}
-
-// Remaining weight cell
-.remaining-cell {
-  display: flex;
-  flex-direction: column;
-  gap: 4px;
-  min-width: 120px;
-
-  .remaining-text {
-    font-size: 13px;
-    color: var(--mat-sys-on-surface-variant);
-  }
-}
-
-// Progress bar stock level variants
-mat-progress-bar {
-  &.critical {
-    --mat-progress-bar-active-indicator-color: #{$color-critical};
-  }
-
-  &.low {
-    --mat-progress-bar-active-indicator-color: #{$color-low};
-  }
-
-  &.moderate {
-    --mat-progress-bar-active-indicator-color: #{$color-moderate};
-  }
-
-  &.healthy {
-    --mat-progress-bar-active-indicator-color: #{$color-healthy};
-  }
-}
-
-// Stock level chip variants
-mat-chip {
-  min-height: 32px !important;
-  font-size: 12px !important;
-
-  &.critical {
-    background-color: rgba($color-critical, 0.15) !important;
-    color: $color-critical;
-
-    mat-icon {
-      color: $color-critical;
-    }
-  }
-
-  &.low {
-    background-color: rgba($color-low, 0.15) !important;
-    color: $color-low;
-
-    mat-icon {
-      color: $color-low;
-    }
-  }
-
-  &.moderate {
-    background-color: rgba($color-moderate, 0.1) !important;
-    color: $color-moderate;
-
-    mat-icon {
-      color: $color-moderate;
-    }
-  }
-
-  &.healthy {
-    background-color: rgba($color-healthy, 0.1) !important;
-    color: $color-healthy;
-
-    mat-icon {
-      color: $color-healthy;
-    }
-  }
-
-  mat-icon {
-    font-size: 16px !important;
-    width: 16px !important;
-    height: 16px !important;
-    margin-right: 4px;
-  }
-}
-
-// Status badge
-.status-badge {
-  display: inline-flex;
-  align-items: center;
-  padding: 4px 12px;
-  border-radius: 12px;
-  font-size: 12px;
-  font-weight: 600;
-  text-transform: uppercase;
-  letter-spacing: 0.04em;
-
-  &.active {
-    background-color: rgba($color-active, 0.12);
-    color: $color-active;
-  }
-
-  &.inactive {
-    background-color: rgba($color-inactive, 0.12);
-    color: $color-inactive;
-  }
-}
-
-// Empty state
-.empty-state {
-  display: flex;
-  flex-direction: column;
-  align-items: center;
-  justify-content: center;
-  padding: 48px $spacing-unit * 2;
-  color: var(--mat-sys-on-surface-variant);
-
-  mat-icon {
-    font-size: 48px !important;
-    width: 48px !important;
-    height: 48px !important;
-    opacity: 0.4;
-    margin-bottom: $spacing-unit * 2;
-  }
-
-  p {
-    font-size: 16px;
-    margin: 0;
-  }
-}

frontend/src/app/components/filament-table/filament-table.component.spec.ts

@@ -1,88 +0,0 @@
-import { describe, it, expect } from 'vitest';
-import {
-  Filament,
-  StockLevel,
-  getRemainingPercent,
-  classifyStockLevel,
-} from '../../models/filament.model';
-
-/** Create a test filament with defaults — override specific fields */
-function createFilament(overrides: Partial<Filament> = {}): Filament {
-  return {
-    id: '00000000-0000-0000-0000-000000000001',
-    materialBaseId: '10000000-0000-0000-0000-000000000001',
-    materialBaseName: 'PLA',
-    materialFinishId: '20000000-0000-0000-0000-000000000001',
-    materialFinishName: 'Basic',
-    materialModifierId: null,
-    materialModifierName: null,
-    brand: 'Bambu Lab',
-    colorName: 'White',
-    colorHex: '#FFFFFF',
-    weightTotalGrams: 1000,
-    weightRemainingGrams: 750,
-    filamentDiameterMm: 1.75,
-    spoolSerial: 'SN-001',
-    purchasePrice: null,
-    purchaseDate: null,
-    isActive: true,
-    createdAt: '2026-01-01T00:00:00Z',
-    updatedAt: '2026-01-01T00:00:00Z',
-    qrCodeUrl: '',
-    ...overrides,
-  };
-}
-
-describe('getRemainingPercent', () => {
-  it('should return correct percentage', () => {
-    const filament = createFilament({ weightTotalGrams: 1000, weightRemainingGrams: 250 });
-    expect(getRemainingPercent(filament)).toBe(25);
-  });
-
-  it('should return 0 when total weight is 0', () => {
-    const filament = createFilament({ weightTotalGrams: 0, weightRemainingGrams: 0 });
-    expect(getRemainingPercent(filament)).toBe(0);
-  });
-
-  it('should cap at 100%', () => {
-    const filament = createFilament({ weightTotalGrams: 100, weightRemainingGrams: 200 });
-    expect(getRemainingPercent(filament)).toBe(100);
-  });
-
-  it('should floor at 0%', () => {
-    const filament = createFilament({ weightTotalGrams: 100, weightRemainingGrams: -10 });
-    expect(getRemainingPercent(filament)).toBe(0);
-  });
-});
-
-describe('classifyStockLevel', () => {
-  it('should classify as critical when ≤10%', () => {
-    const filament = createFilament({ weightTotalGrams: 1000, weightRemainingGrams: 50 });
-    expect(classifyStockLevel(filament)).toBe('critical');
-  });
-
-  it('should classify as critical at exactly 10%', () => {
-    const filament = createFilament({ weightTotalGrams: 1000, weightRemainingGrams: 100 });
-    expect(classifyStockLevel(filament)).toBe('critical');
-  });
-
-  it('should classify as low when ≤25%', () => {
-    const filament = createFilament({ weightTotalGrams: 1000, weightRemainingGrams: 200 });
-    expect(classifyStockLevel(filament)).toBe('low');
-  });
-
-  it('should classify as moderate when ≤50%', () => {
-    const filament = createFilament({ weightTotalGrams: 1000, weightRemainingGrams: 400 });
-    expect(classifyStockLevel(filament)).toBe('moderate');
-  });
-
-  it('should classify as healthy when >50%', () => {
-    const filament = createFilament({ weightTotalGrams: 1000, weightRemainingGrams: 750 });
-    expect(classifyStockLevel(filament)).toBe('healthy');
-  });
-
-  it('should classify 0 grams remaining as critical', () => {
-    const filament = createFilament({ weightTotalGrams: 1000, weightRemainingGrams: 0 });
-    expect(classifyStockLevel(filament)).toBe('critical');
-  });
-});

frontend/src/app/components/filament-table/filament-table.component.ts

@@ -1,304 +0,0 @@
-import {
-  ChangeDetectionStrategy,
-  Component,
-  Input,
-  OnInit,
-  computed,
-  inject,
-  signal,
-} from '@angular/core';
-import { FilamentService } from '../../services/filament.service';
-import { CommonModule } from '@angular/common';
-import { MatTableModule } from '@angular/material/table';
-import { MatChipsModule } from '@angular/material/chips';
-import { MatIconModule } from '@angular/material/icon';
-import { MatProgressBarModule } from '@angular/material/progress-bar';
-import { MatTooltipModule } from '@angular/material/tooltip';
-import { MatSortModule, Sort } from '@angular/material/sort';
-import { FilamentFilterComponent, FilamentFilterState } from '../filament-filter/filament-filter.component';
-import {
-  Filament,
-  StockLevel,
-  getRemainingPercent,
-  classifyStockLevel,
-} from '../../models/filament.model';
-
-/** Display column definitions for the filament table */
-export type FilamentColumn =
-  | 'color'
-  | 'material'
-  | 'brand'
-  | 'serial'
-  | 'remaining'
-  | 'cost'
-  | 'usage'
-  | 'stockLevel'
-  | 'status';
-
-@Component({
-  selector: 'app-filament-table',
-  standalone: true,
-  imports: [
-    CommonModule,
-    MatTableModule,
-    MatChipsModule,
-    MatIconModule,
-    MatProgressBarModule,
-    MatTooltipModule,
-    MatSortModule,
-    FilamentFilterComponent,
-  ],
-  templateUrl: './filament-table.component.html',
-  styleUrl: './filament-table.component.scss',
-  changeDetection: ChangeDetectionStrategy.OnPush,
-})
-export class FilamentTableComponent implements OnInit {
-  private readonly filamentService = inject(FilamentService);
-
-  /** Filament data — reactive signal driven by FilamentService */
-  readonly filaments = this.filamentService.filaments;
-
-  /** Columns to display — defaults to all columns */
-  @Input()
-  set displayedColumns(cols: FilamentColumn[]) {
-    this._displayedColumns.set(cols);
-  }
-  get displayedColumns(): FilamentColumn[] {
-    return this._displayedColumns();
-  }
-  private readonly _displayedColumns = signal<FilamentColumn[]>([
-    'color',
-    'material',
-    'brand',
-    'serial',
-    'remaining',
-    'cost',
-    'usage',
-    'stockLevel',
-    'status',
-  ]);
-
-  /** Default columns for template binding */
-  readonly columns = this._displayedColumns;
-
-  /** Current filter state */
-  readonly filterState = signal<FilamentFilterState>({
-    materialBaseNames: [],
-    colorSearch: '',
-    lowStockOnly: false,
-    activeOnly: false,
-  });
-
-  /** Sorted filament data */
-  readonly sortedFilaments = signal<Filament[]>([]);
-
-  /** Computed: filtered + sorted filament data for display */
-  readonly filteredFilaments = computed(() => {
-    const data = this.sortedFilaments();
-    const filters = this.filterState();
-    return data.filter((f) => this.matchesFilter(f, filters));
-  });
-
-  /** Computed: count of low/critical spools */
-  readonly lowStockCount = computed(() =>
-    this.filaments().filter(
-      (f) => classifyStockLevel(f) === 'low' || classifyStockLevel(f) === 'critical'
-    ).length
-  );
-
-  /** Computed: count of critical spools */
-  readonly criticalCount = computed(() =>
-    this.filaments().filter((f) => classifyStockLevel(f) === 'critical').length
-  );
-
-  ngOnInit(): void {
-    // Initialize sorted data from FilamentService
-    this.sortedFilaments.set([...this.filaments()]);
-  }
-
-  /** Update filament data — called externally or from a SignalR handler */
-  updateFilaments(data: Filament[]): void {
-    this.filamentService.setFilaments(data);
-    this.sortedFilaments.set([...data]);
-  }
-
-  /** All filament data — for the filter component to derive material options */
-  readonly allFilaments = this.filaments;
-
-  /** Handle sort changes from MatSort */
-  sortData(sort: Sort): void {
-    const data = [...this.filaments()];
-    if (!sort.active || sort.direction === '') {
-      this.sortedFilaments.set(data);
-      return;
-    }
-    const sorted = data.sort((a, b) => {
-      const isAsc = sort.direction === 'asc';
-      switch (sort.active as FilamentColumn) {
-        case 'material':
-          return compare(a.materialBaseName, b.materialBaseName, isAsc);
-        case 'brand':
-          return compare(a.brand, b.brand, isAsc);
-        case 'serial':
-          return compare(a.spoolSerial, b.spoolSerial, isAsc);
-        case 'remaining':
-          return compare(
-            getRemainingPercent(a),
-            getRemainingPercent(b),
-            isAsc
-          );
-        case 'cost':
-          return compare(
-            a.purchasePrice ?? 0,
-            b.purchasePrice ?? 0,
-            isAsc
-          );
-        case 'usage':
-          return compare(
-            a.weightTotalGrams - a.weightRemainingGrams,
-            b.weightTotalGrams - b.weightRemainingGrams,
-            isAsc
-          );
-        case 'stockLevel':
-          return compare(
-            stockLevelOrder(classifyStockLevel(a)),
-            stockLevelOrder(classifyStockLevel(b)),
-            isAsc
-          );
-        case 'status':
-          return compare(
-            a.isActive ? 0 : 1,
-            b.isActive ? 0 : 1,
-            isAsc
-          );
-        default:
-          return 0;
-      }
-    });
-    this.sortedFilaments.set(sorted);
-  }
-
-  /** Handle filter changes from FilamentFilterComponent */
-  onFilterChange(state: FilamentFilterState): void {
-    this.filterState.set(state);
-  }
-
-  /** Check if a filament matches the current filter state */
-  private matchesFilter(filament: Filament, filters: FilamentFilterState): boolean {
-    // Material filter — empty means all
-    if (
-      filters.materialBaseNames.length > 0 &&
-      !filters.materialBaseNames.includes(filament.materialBaseName)
-    ) {
-      return false;
-    }
-
-    // Color search — empty means all
-    if (
-      filters.colorSearch &&
-      !filament.colorName.toLowerCase().includes(filters.colorSearch) &&
-      !filament.colorHex.toLowerCase().includes(filters.colorSearch)
-    ) {
-      return false;
-    }
-
-    // Low stock filter — show only critical/low
-    if (filters.lowStockOnly) {
-      const level = classifyStockLevel(filament);
-      if (level !== 'critical' && level !== 'low') {
-        return false;
-      }
-    }
-
-    // Active only filter
-    if (filters.activeOnly && !filament.isActive) {
-      return false;
-    }
-
-    return true;
-  }
-
-  /** Template helper: get remaining percent */
-  getRemainingPercent = getRemainingPercent;
-
-  /** Template helper: classify stock level */
-  classifyStockLevel = classifyStockLevel;
-
-  /** Template helper: stock level icon */
-  stockLevelIcon(level: StockLevel): string {
-    switch (level) {
-      case 'critical':
-        return 'error';
-      case 'low':
-        return 'warning';
-      case 'moderate':
-        return 'info';
-      case 'healthy':
-        return 'check_circle';
-    }
-  }
-
-  /** Template helper: stock level label */
-  stockLevelLabel(level: StockLevel): string {
-    switch (level) {
-      case 'critical':
-        return 'Critical';
-      case 'low':
-        return 'Low';
-      case 'moderate':
-        return 'Moderate';
-      case 'healthy':
-        return 'Healthy';
-    }
-  }
-
-  /** Template helper: format remaining weight */
-  formatWeight(grams: number): string {
-    if (grams >= 1000) {
-      return `${(grams / 1000).toFixed(1)}kg`;
-    }
-    return `${Math.round(grams)}g`;
-  }
-
-  /** Template helper: format currency */
-  formatCurrency(value: number): string {
-    return new Intl.NumberFormat('en-US', {
-      style: 'currency',
-      currency: 'USD',
-      minimumFractionDigits: 2,
-      maximumFractionDigits: 2,
-    }).format(value);
-  }
-
-  /** Template helper: compute cost per gram for a filament */
-  getCostPerGram(filament: Filament): number | null {
-    if (filament.purchasePrice === null || filament.purchasePrice === 0 || filament.weightTotalGrams <= 0) {
-      return null;
-    }
-    return filament.purchasePrice / filament.weightTotalGrams;
-  }
-
-  /** Template helper: compute grams used for a filament */
-  getGramsUsed(filament: Filament): number {
-    return filament.weightTotalGrams - filament.weightRemainingGrams;
-  }
-}
-
-/** Compare helper for sorting */
-function compare(a: number | string, b: number | string, isAsc: boolean): number {
-  return (a < b ? -1 : a > b ? 1 : 0) * (isAsc ? 1 : -1);
-}
-
-/** Stock level sort order (critical=0, healthy=3) */
-function stockLevelOrder(level: StockLevel): number {
-  switch (level) {
-    case 'critical':
-      return 0;
-    case 'low':
-      return 1;
-    case 'moderate':
-      return 2;
-    case 'healthy':
-      return 3;
-  }
-}

frontend/src/app/components/inventory-summary/inventory-summary.component.html

@@ -1,145 +0,0 @@
-<!-- Inventory Dashboard Summary — filament metrics at a glance -->
-<section class="inventory-summary" role="region" aria-label="Inventory summary">
-
-  <!-- Loading State -->
-  @if (loading()) {
-    <div class="summary-loading" role="status" aria-live="polite">
-      <mat-icon aria-hidden="true" class="spin">sync</mat-icon>
-      <span>Loading inventory...</span>
-    </div>
-  }
-
-  <!-- Error State -->
-  @else if (error()) {
-    <div class="summary-error" role="alert" aria-live="assertive">
-      <mat-icon aria-hidden="true">error_outline</mat-icon>
-      <span>{{ error() }}</span>
-      <button class="retry-btn" (click)="refresh()" aria-label="Retry loading inventory">
-        <mat-icon aria-hidden="true">refresh</mat-icon>
-        Retry
-      </button>
-    </div>
-  }
-
-  <!-- Loaded State -->
-  @else {
-    <!-- Health Status Indicator -->
-    <div class="summary-item health-status"
-         [class]="healthClass()"
-         [matTooltip]="healthLabel()"
-         matTooltipPosition="below">
-      <mat-icon aria-hidden="true">
-        @switch (healthClass()) {
-          @case ('critical') { error }
-          @case ('low') { warning }
-          @default { check_circle }
-        }
-      </mat-icon>
-      <span class="health-text">{{ healthLabel() }}</span>
-    </div>
-
-    <!-- Total Spool Count -->
-    <div class="summary-item metric-card"
-         matTooltip="Total filament spools in inventory"
-         matTooltipPosition="below">
-      <mat-icon aria-hidden="true" class="metric-icon">inventory_2</mat-icon>
-      <div class="metric-content">
-        <span class="metric-value">{{ totalCount() }}</span>
-        <span class="metric-label">Total Spools</span>
-      </div>
-      @if (activeCount() < totalCount()) {
-        <span class="metric-detail">{{ activeCount() }} active</span>
-      }
-    </div>
-
-    <!-- Low Stock Count -->
-    <div class="summary-item metric-card"
-         [class.has-alert]="hasLowStock()"
-         [class.has-critical]="hasCritical()"
-         [matTooltip]="hasCritical()
-           ? criticalCount() + ' critical, ' + (lowStockCount() - criticalCount()) + ' low'
-           : hasLowStock()
-             ? lowStockCount() + ' spools at or below 25% remaining'
-             : 'All spools above 25% remaining'"
-         matTooltipPosition="below">
-      <mat-icon aria-hidden="true" class="metric-icon">
-        @if (hasCritical()) { error }
-        @else if (hasLowStock()) { warning }
-        @else { check_circle }
-      </mat-icon>
-      <div class="metric-content">
-        <span class="metric-value">{{ lowStockCount() }}</span>
-        <span class="metric-label">Low Stock</span>
-      </div>
-      @if (hasCritical()) {
-        <span class="metric-detail critical-detail">{{ criticalCount() }} critical</span>
-      }
-    </div>
-
-    <!-- Estimated Total Value -->
-    <div class="summary-item metric-card"
-         matTooltip="Estimated total value of active spools"
-         matTooltipPosition="below">
-      <mat-icon aria-hidden="true" class="metric-icon">payments</mat-icon>
-      <div class="metric-content">
-        <span class="metric-value">{{ formatCurrency(totalValue()) }}</span>
-        <span class="metric-label">Est. Value</span>
-      </div>
-    </div>
-
-    <!-- Average Cost per Gram -->
-    @if (avgCostPerGram() !== null) {
-      <div class="summary-item metric-card"
-           matTooltip="Average cost per gram across priced, active spools"
-           matTooltipPosition="below">
-        <mat-icon aria-hidden="true" class="metric-icon">scale</mat-icon>
-        <div class="metric-content">
-          <span class="metric-value">${{ avgCostPerGram()!.toFixed(2) }}/g</span>
-          <span class="metric-label">Avg Cost/g</span>
-        </div>
-      </div>
-    }
-
-    <!-- Total Usage -->
-    <div class="summary-item metric-card"
-         matTooltip="Total filament used across all spools"
-         matTooltipPosition="below">
-      <mat-icon aria-hidden="true" class="metric-icon">trending_down</mat-icon>
-      <div class="metric-content">
-        <span class="metric-value">{{ formatWeight(totalGramsUsed()) }}</span>
-        <span class="metric-label">Total Used</span>
-      </div>
-    </div>
-
-    <!-- Estimated Used Value -->
-    @if (estimatedUsedValue() !== null) {
-      <div class="summary-item metric-card"
-           matTooltip="Estimated value of filament consumed"
-           matTooltipPosition="below">
-        <mat-icon aria-hidden="true" class="metric-icon">receipt_long</mat-icon>
-        <div class="metric-content">
-          <span class="metric-value">{{ formatCurrency(estimatedUsedValue()!) }}</span>
-          <span class="metric-label">Used Value</span>
-        </div>
-      </div>
-    }
-
-    <!-- Overall Remaining Stock Bar -->
-    <div class="summary-item metric-card stock-bar-card"
-         matTooltip="{{ formatWeight(totalRemainingGrams()) }} of {{ formatWeight(totalCapacityGrams()) }} remaining"
-         matTooltipPosition="below">
-      <mat-icon aria-hidden="true" class="metric-icon">line_weight</mat-icon>
-      <div class="metric-content stock-bar-content">
-        <div class="stock-bar-header">
-          <span class="metric-value">{{ overallRemainingPercent() }}%</span>
-          <span class="metric-label">Remaining</span>
-        </div>
-        <mat-progress-bar
-          mode="determinate"
-          [value]="overallRemainingPercent()"
-          [ngClass]="healthClass()">
-        </mat-progress-bar>
-      </div>
-    </div>
-  }
-</section>

frontend/src/app/components/inventory-summary/inventory-summary.component.scss

@@ -1,257 +0,0 @@
-/**
- * Inventory Summary Component Styles
- * Touch-optimized for kiosk (Raspberry Pi 5) and mobile PWA
- * Matches the existing dark theme from app.scss
- */
-
-// Touch-optimized sizing
-$touch-target-min: 48px;
-$kiosk-font-primary: 24px;
-$mobile-font-primary: 18px;
-$spacing-unit: 8px;
-
-// Status colors — high contrast for workshop/bright environments
-$color-healthy: #4ade70;    // Green
-$color-low: #fbbf24;        // Amber/Yellow
-$color-critical: #f87171;   // Red
-$color-bg: #1a1a2e;         // Matches app.scss
-$color-text: #e0e0e0;
-$color-text-muted: rgba(255, 255, 255, 0.7);
-$color-card-bg: rgba(255, 255, 255, 0.05);
-$color-card-border: rgba(255, 255, 255, 0.1);
-
-.inventory-summary {
-  display: flex;
-  align-items: stretch;
-  gap: $spacing-unit * 2;
-  padding: $spacing-unit * 2;
-  overflow-x: auto;
-  -webkit-overflow-scrolling: touch;
-  scrollbar-width: thin;
-
-  @media (max-width: 600px) {
-    flex-wrap: wrap;
-    padding: $spacing-unit;
-    gap: $spacing-unit;
-  }
-}
-
-// Health status indicator
-.health-status {
-  display: flex;
-  align-items: center;
-  gap: $spacing-unit;
-  padding: $spacing-unit $spacing-unit * 2;
-  border-radius: 24px;
-  min-height: $touch-target-min;
-  white-space: nowrap;
-  transition: background-color 0.3s ease;
-
-  &.healthy {
-    background-color: rgba($color-healthy, 0.15);
-    color: $color-healthy;
-  }
-
-  &.low {
-    background-color: rgba($color-low, 0.15);
-    color: $color-low;
-  }
-
-  &.critical {
-    background-color: rgba($color-critical, 0.15);
-    color: $color-critical;
-  }
-
-  .health-text {
-    font-size: 14px;
-    font-weight: 600;
-    letter-spacing: 0.02em;
-
-    @media (max-width: 480px) {
-      font-size: 12px;
-    }
-  }
-
-  mat-icon {
-    font-size: 20px !important;
-    width: 20px !important;
-    height: 20px !important;
-  }
-}
-
-// Metric card
-.metric-card {
-  display: flex;
-  align-items: center;
-  gap: $spacing-unit;
-  padding: $spacing-unit $spacing-unit * 2;
-  background-color: $color-card-bg;
-  border: 1px solid $color-card-border;
-  border-radius: 12px;
-  min-height: $touch-target-min;
-  white-space: nowrap;
-  transition: border-color 0.2s ease, background-color 0.2s ease;
-
-  &:hover {
-    border-color: rgba(255, 255, 255, 0.2);
-    background-color: rgba(255, 255, 255, 0.08);
-  }
-
-  @media (max-width: 480px) {
-    padding: $spacing-unit;
-  }
-
-  &.has-alert {
-    border-color: rgba($color-low, 0.4);
-  }
-
-  &.has-critical {
-    border-color: rgba($color-critical, 0.5);
-    background-color: rgba($color-critical, 0.08);
-  }
-}
-
-.metric-icon {
-  color: $color-text-muted;
-  font-size: 22px !important;
-  width: 22px !important;
-  height: 22px !important;
-
-  .has-alert & {
-    color: $color-low;
-  }
-
-  .has-critical & {
-    color: $color-critical;
-  }
-}
-
-.metric-content {
-  display: flex;
-  flex-direction: column;
-  gap: 2px;
-}
-
-.metric-value {
-  font-size: $kiosk-font-primary;
-  font-weight: 700;
-  line-height: 1.2;
-  color: $color-text;
-
-  @media (max-width: 480px) {
-    font-size: $mobile-font-primary;
-  }
-}
-
-.metric-label {
-  font-size: 11px;
-  color: $color-text-muted;
-  text-transform: uppercase;
-  letter-spacing: 0.08em;
-}
-
-.metric-detail {
-  font-size: 11px;
-  color: $color-text-muted;
-  margin-left: $spacing-unit;
-
-  &.critical-detail {
-    color: $color-critical;
-    font-weight: 600;
-  }
-}
-
-// Stock bar card
-.stock-bar-card {
-  flex: 1 1 200px;
-  min-width: 180px;
-}
-
-.stock-bar-content {
-  flex: 1;
-  min-width: 0;
-}
-
-.stock-bar-header {
-  display: flex;
-  align-items: baseline;
-  gap: $spacing-unit;
-  margin-bottom: 4px;
-}
-
-// Progress bar color classes
-::ng-deep .mat-mdc-progress-bar {
-  &.healthy .mdc-linear-progress__bar-inner {
-    background-color: $color-healthy !important;
-  }
-
-  &.low .mdc-linear-progress__bar-inner {
-    background-color: $color-low !important;
-  }
-
-  &.critical .mdc-linear-progress__bar-inner {
-    background-color: $color-critical !important;
-  }
-}
-
-// Loading state
-.summary-loading {
-  display: flex;
-  align-items: center;
-  gap: $spacing-unit;
-  padding: $spacing-unit * 2;
-  color: $color-text-muted;
-  font-size: 14px;
-
-  .spin {
-    animation: spin 1s linear infinite;
-  }
-}
-
-@keyframes spin {
-  0% { transform: rotate(0deg); }
-  100% { transform: rotate(360deg); }
-}
-
-// Error state
-.summary-error {
-  display: flex;
-  align-items: center;
-  gap: $spacing-unit;
-  padding: $spacing-unit * 2;
-  background-color: rgba($color-critical, 0.1);
-  border: 1px solid rgba($color-critical, 0.3);
-  border-radius: 12px;
-  color: $color-critical;
-  font-size: 14px;
-
-  .retry-btn {
-    display: flex;
-    align-items: center;
-    gap: 4px;
-    background: transparent;
-    border: 1px solid rgba($color-critical, 0.4);
-    color: $color-critical;
-    padding: 4px 12px;
-    border-radius: 8px;
-    cursor: pointer;
-    font-size: 13px;
-    min-height: $touch-target-min - 8px;
-    transition: background-color 0.2s ease;
-
-    &:hover {
-      background-color: rgba($color-critical, 0.15);
-    }
-
-    mat-icon {
-      font-size: 16px !important;
-      width: 16px !important;
-      height: 16px !important;
-    }
-  }
-}
-
-// Summary item base
-.summary-item {
-  flex-shrink: 0;
-}

frontend/src/app/components/inventory-summary/inventory-summary.component.ts

@@ -1,207 +0,0 @@
-import {
-  ChangeDetectionStrategy,
-  Component,
-  OnDestroy,
-  OnInit,
-  computed,
-  inject,
-  signal,
-} from '@angular/core';
-import { CommonModule } from '@angular/common';
-import { MatIconModule } from '@angular/material/icon';
-import { MatChipsModule } from '@angular/material/chips';
-import { MatTooltipModule } from '@angular/material/tooltip';
-import { MatProgressBarModule } from '@angular/material/progress-bar';
-import { FilamentService } from '../../services/filament.service';
-import {
-  classifyStockLevel,
-} from '../../models/filament.model';
-import { Subscription } from 'rxjs';
-
-/**
- * Inventory Dashboard Summary — shows filament inventory at a glance.
- *
- * Displays:
- * - Total filament spool count
- * - Low stock count (spools ≤25% remaining, i.e. "low" or "critical")
- * - Estimated total filament value (sum of purchase prices for active spools)
- *
- * Data is sourced from the shared FilamentService signal,
- * which is loaded on init and can be refreshed via refresh().
- */
-@Component({
-  selector: 'app-inventory-summary',
-  standalone: true,
-  imports: [
-    CommonModule,
-    MatIconModule,
-    MatChipsModule,
-    MatTooltipModule,
-    MatProgressBarModule,
-  ],
-  templateUrl: './inventory-summary.component.html',
-  styleUrls: ['./inventory-summary.component.scss'],
-  changeDetection: ChangeDetectionStrategy.OnPush,
-})
-export class InventorySummaryComponent implements OnInit, OnDestroy {
-  private readonly filamentService = inject(FilamentService);
-  private subscription: Subscription | null = null;
-
-  /** All filament data — reactive signal from shared service */
-  readonly filaments = this.filamentService.filaments;
-
-  /** Loading state */
-  readonly loading = signal<boolean>(true);
-
-  /** Error state */
-  readonly error = signal<string | null>(null);
-
-  /** Computed: total number of filament spools */
-  readonly totalCount = computed(() => this.filaments().length);
-
-  /** Computed: count of active spools */
-  readonly activeCount = computed(
-    () => this.filaments().filter((f) => f.isActive).length
-  );
-
-  /** Computed: count of low/critical stock spools (≤25% remaining) */
-  readonly lowStockCount = computed(
-    () =>
-      this.filaments().filter(
-        (f) =>
-          classifyStockLevel(f) === 'low' ||
-          classifyStockLevel(f) === 'critical'
-      ).length
-  );
-
-  /** Computed: count of critically low spools (≤10% remaining) */
-  readonly criticalCount = computed(
-    () =>
-      this.filaments().filter((f) => classifyStockLevel(f) === 'critical')
-        .length
-  );
-
-  /** Computed: estimated total value of active spools */
-  readonly totalValue = computed(() =>
-    this.filaments()
-      .filter((f) => f.isActive && f.purchasePrice !== null)
-      .reduce((sum, f) => sum + (f.purchasePrice ?? 0), 0)
-  );
-
-  /** Computed: average cost per gram across active spools with a price */
-  readonly avgCostPerGram = computed(() => {
-    const priced = this.filaments().filter(
-      (f) => f.isActive && f.purchasePrice !== null && f.purchasePrice! > 0 && f.weightTotalGrams > 0
-    );
-    if (priced.length === 0) return null;
-    const totalCost = priced.reduce((sum, f) => sum + f.purchasePrice!, 0);
-    const totalWeight = priced.reduce((sum, f) => sum + f.weightTotalGrams, 0);
-    return totalWeight > 0 ? totalCost / totalWeight : null;
-  });
-
-  /** Computed: total grams used across all spools */
-  readonly totalGramsUsed = computed(() =>
-    this.filaments().reduce(
-      (sum, f) => sum + (f.weightTotalGrams - f.weightRemainingGrams),
-      0
-    )
-  );
-
-  /** Computed: total estimated value of used filament */
-  readonly estimatedUsedValue = computed(() => {
-    const priced = this.filaments().filter(
-      (f) => f.isActive && f.purchasePrice !== null && f.purchasePrice! > 0 && f.weightTotalGrams > 0
-    );
-    if (priced.length === 0) return null;
-    return priced.reduce((sum, f) => {
-      const usedFraction = (f.weightTotalGrams - f.weightRemainingGrams) / f.weightTotalGrams;
-      return sum + f.purchasePrice! * usedFraction;
-    }, 0);
-  });
-
-  /** Computed: total remaining weight across all spools in grams */
-  readonly totalRemainingGrams = computed(() =>
-    this.filaments().reduce((sum, f) => sum + f.weightRemainingGrams, 0)
-  );
-
-  /** Computed: total capacity weight across all spools in grams */
-  readonly totalCapacityGrams = computed(() =>
-    this.filaments().reduce((sum, f) => sum + f.weightTotalGrams, 0)
-  );
-
-  /** Computed: overall remaining percentage */
-  readonly overallRemainingPercent = computed(() => {
-    const capacity = this.totalCapacityGrams();
-    if (capacity <= 0) return 0;
-    return Math.round(
-      (this.totalRemainingGrams() / capacity) * 100
-    );
-  });
-
-  /** Computed: whether to show a low-stock alert */
-  readonly hasLowStock = computed(() => this.lowStockCount() > 0);
-
-  /** Computed: whether to show a critical-stock alert */
-  readonly hasCritical = computed(() => this.criticalCount() > 0);
-
-  /** Computed: status label for the inventory health */
-  readonly healthLabel = computed(() => {
-    if (this.hasCritical()) return 'Critical Stock';
-    if (this.hasLowStock()) return 'Low Stock Alert';
-    return 'Stock Healthy';
-  });
-
-  /** Computed: health status color class */
-  readonly healthClass = computed(() => {
-    if (this.hasCritical()) return 'critical';
-    if (this.hasLowStock()) return 'low';
-    return 'healthy';
-  });
-
-  ngOnInit(): void {
-    this.loadFilaments();
-  }
-
-  ngOnDestroy(): void {
-    this.subscription?.unsubscribe();
-  }
-
-  /** Load filament data from the API via FilamentService */
-  loadFilaments(): void {
-    this.loading.set(true);
-    this.error.set(null);
-    this.subscription = this.filamentService.getFilaments().subscribe({
-      next: () => {
-        this.loading.set(false);
-      },
-      error: (err) => {
-        console.error('Failed to load filaments:', err);
-        this.error.set('Failed to load inventory data');
-        this.loading.set(false);
-      },
-    });
-  }
-
-  /** Refresh data — called externally when data changes (e.g., SignalR notification) */
-  refresh(): void {
-    this.loadFilaments();
-  }
-
-  /** Format weight for display */
-  formatWeight(grams: number): string {
-    if (grams >= 1000) {
-      return `${(grams / 1000).toFixed(1)}kg`;
-    }
-    return `${Math.round(grams)}g`;
-  }
-
-  /** Format currency for display */
-  formatCurrency(value: number): string {
-    return new Intl.NumberFormat('en-US', {
-      style: 'currency',
-      currency: 'USD',
-      minimumFractionDigits: 2,
-      maximumFractionDigits: 2,
-    }).format(value);
-  }
-}

frontend/src/app/models/agent.model.ts

@@ -1,24 +0,0 @@
-/**
- * Represents the status of a single agent/printer in the system.
- */
-export type AgentStatus = 'active' | 'idle' | 'thinking' | 'error';
-
-export interface AgentSummary {
-  /** Total number of agents in the system */
-  total: number;
-  /** Number of currently active agents */
-  active: number;
-  /** Number of currently idle agents */
-  idle: number;
-  /** Number of currently thinking/processing agents */
-  thinking: number;
-  /** Number of agents in error state */
-  error: number;
-}
-
-export interface SystemHealth {
-  /** Whether the SignalR connection is live */
-  connected: boolean;
-  /** Overall system health: healthy, degraded, or down */
-  status: 'healthy' | 'degraded' | 'down';
-}

frontend/src/app/models/filament.model.ts

@@ -1,100 +0,0 @@
-/**
- * Filament model matching the Extrudex backend FilamentResponse DTO.
- * Used for displaying spool inventory in the filament table UI.
- */
-export interface Filament {
-  /** Unique identifier for the filament spool. */
-  id: string;
-
-  /** Foreign key to the base material. */
-  materialBaseId: string;
-
-  /** Name of the base material (e.g., "PLA", "PETG"). */
-  materialBaseName: string;
-
-  /** Foreign key to the material finish. */
-  materialFinishId: string;
-
-  /** Name of the material finish (e.g., "Basic", "Matte"). */
-  materialFinishName: string;
-
-  /** Foreign key to the optional material modifier. */
-  materialModifierId: string | null;
-
-  /** Name of the material modifier (e.g., "Carbon Fiber"). Null if none. */
-  materialModifierName: string | null;
-
-  /** Brand name (e.g., "Bambu Lab", "Polymaker"). */
-  brand: string;
-
-  /** Human-readable color name (e.g., "Fire Engine Red"). */
-  colorName: string;
-
-  /** Hex color code (e.g., "#FF0000"). */
-  colorHex: string;
-
-  /** Total spool weight in grams when full. */
-  weightTotalGrams: number;
-
-  /** Current remaining weight in grams. */
-  weightRemainingGrams: number;
-
-  /** Filament diameter in millimeters. Typically 1.75mm. */
-  filamentDiameterMm: number;
-
-  /** Manufacturer-assigned serial number. */
-  spoolSerial: string;
-
-  /** Purchase price per spool. Null if not tracked. */
-  purchasePrice: number | null;
-
-  /** Date the spool was purchased or received. */
-  purchaseDate: string | null;
-
-  /** Whether the spool is currently active and available. */
-  isActive: boolean;
-
-  /** Timestamp when this record was created (UTC). */
-  createdAt: string;
-
-  /** Timestamp when this record was last updated (UTC). */
-  updatedAt: string;
-
-  /** URL to the QR code image for this spool. */
-  qrCodeUrl: string;
-}
-
-/**
- * Stock level classification for low stock indicators.
- * - critical: ≤ 10% remaining
- * - low: ≤ 25% remaining
- * - moderate: ≤ 50% remaining
- * - healthy: > 50% remaining
- */
-export type StockLevel = 'critical' | 'low' | 'moderate' | 'healthy';
-
-/**
- * Compute the remaining weight percentage for a filament spool.
- * Returns a value from 0 to 100.
- */
-export function getRemainingPercent(filament: Filament): number {
-  if (filament.weightTotalGrams <= 0) return 0;
-  const pct = (filament.weightRemainingGrams / filament.weightTotalGrams) * 100;
-  return Math.min(Math.max(pct, 0), 100);
-}
-
-/**
- * Classify the stock level based on remaining percentage.
- * Thresholds:
- *   critical  — ≤ 10%  (nearly empty, red alert)
- *   low       — ≤ 25%  (getting low, amber warning)
- *   moderate  — ≤ 50%  (half or less, yellow info)
- *   healthy   — > 50%  (plenty left, green OK)
- */
-export function classifyStockLevel(filament: Filament): StockLevel {
-  const pct = getRemainingPercent(filament);
-  if (pct <= 10) return 'critical';
-  if (pct <= 25) return 'low';
-  if (pct <= 50) return 'moderate';
-  return 'healthy';
-}

frontend/src/app/models/material.model.ts

@@ -1,50 +0,0 @@
-/**
- * Material lookup models matching the Extrudex backend Material DTOs.
- * Used for populating dropdowns in the filament add/edit form.
- */
-
-/** Material base (e.g., PLA, PETG, ABS). */
-export interface MaterialBase {
-  /** Unique identifier. */
-  id: string;
-  /** Human-readable name (e.g., "PLA", "PETG"). */
-  name: string;
-  /** Density in g/cm³. */
-  densityGperCm3: number;
-  /** Created timestamp (UTC). */
-  createdAt: string;
-  /** Updated timestamp (UTC). */
-  updatedAt: string;
-}
-
-/** Material finish (e.g., Basic, Matte, Silk). */
-export interface MaterialFinish {
-  /** Unique identifier. */
-  id: string;
-  /** Human-readable name (e.g., "Basic", "Matte"). */
-  name: string;
-  /** Foreign key to the parent material base. */
-  materialBaseId: string;
-  /** Name of the parent material base (for display). */
-  materialBaseName: string;
-  /** Created timestamp (UTC). */
-  createdAt: string;
-  /** Updated timestamp (UTC). */
-  updatedAt: string;
-}
-
-/** Material modifier (e.g., Carbon Fiber, Wood Fill). Optional. */
-export interface MaterialModifier {
-  /** Unique identifier. */
-  id: string;
-  /** Human-readable name (e.g., "Carbon Fiber"). */
-  name: string;
-  /** Foreign key to the parent material base. */
-  materialBaseId: string;
-  /** Name of the parent material base (for display). */
-  materialBaseName: string;
-  /** Created timestamp (UTC). */
-  createdAt: string;
-  /** Updated timestamp (UTC). */
-  updatedAt: string;
-}

frontend/src/app/models/paged-response.model.ts

@@ -1,13 +0,0 @@
-/**
- * Generic paged response wrapper matching the Extrudex backend PagedResponse<T>.
- */
-export interface PagedResponse<T> {
-  /** The items in this page. */
-  items: T[];
-  /** Total number of items across all pages. */
-  totalCount: number;
-  /** The current page number (1-based). */
-  pageNumber: number;
-  /** The number of items per page. */
-  pageSize: number;
-}

frontend/src/app/services/filament.service.ts

@@ -1,52 +0,0 @@
-import { Injectable, inject } from '@angular/core';
-import { HttpClient } from '@angular/common/http';
-import { Observable, Subscription } from 'rxjs';
-import { signal } from '@angular/core';
-import { Filament } from '../models/filament.model';
-
-/**
- * API base URL — matches the Extrudex backend.
- * TODO: Move to environment config when environments are set up.
- */
-const API_BASE_URL = '/api/filaments';
-
-/**
- * Service for managing filament inventory data.
- *
- * Provides:
- * - A reactive `filaments` signal for components to bind to
- * - REST methods for GET, POST, DELETE endpoints
- * - Real-time updates via SignalR should be layered on top when the hub is ready
- */
-@Injectable({ providedIn: 'root' })
-export class FilamentService {
-  private readonly http = inject(HttpClient);
-
-  /** Reactive filament data — components read from this signal */
-  readonly filaments = signal<Filament[]>([]);
-
-  /** Fetch all filament spools and update the signal */
-  getFilaments(): Observable<Filament[]> {
-    const req = this.http.get<Filament[]>(API_BASE_URL);
-    req.subscribe({
-      next: (data) => this.filaments.set(data),
-      error: (err) => console.error('Failed to load filaments:', err),
-    });
-    return req;
-  }
-
-  /** Fetch a single filament by ID */
-  getFilament(id: string): Observable<Filament> {
-    return this.http.get<Filament>(`${API_BASE_URL}/${id}`);
-  }
-
-  /** Set filament data directly — used by components or SignalR handlers */
-  setFilaments(data: Filament[]): void {
-    this.filaments.set(data);
-  }
-
-  /** Delete a filament spool by ID */
-  deleteFilament(id: string): Observable<void> {
-    return this.http.delete<void>(`${API_BASE_URL}/${id}`);
-  }
-}

frontend/src/components/ColorSwatch.tsx

@@ -0,0 +1,18 @@
+interface ColorSwatchProps {
+  colorHex: string
+  size?: number
+}
+
+export default function ColorSwatch({ colorHex, size = 24 }: ColorSwatchProps) {
+  return (
+    <div
+      className="rounded-full border border-slate-600 shadow-sm inline-block"
+      style={{
+        backgroundColor: colorHex.startsWith('#') ? colorHex : `#${colorHex}`,
+        width: size,
+        height: size,
+      }}
+      title={colorHex}
+    />
+  )
+}

frontend/src/components/FilamentForm.tsx

@@ -0,0 +1,360 @@
+import { useState, useEffect, useMemo } from 'react'
+import { X, Save, AlertCircle } from 'lucide-react'
+import ColorSwatch from './ColorSwatch'
+import { createFilament, updateFilament, fetchMaterialBases, fetchMaterialFinishes, fetchMaterialModifiers } from '../services/filamentService'
+import type { FilamentSpool, MaterialBase, MaterialFinish, MaterialModifier } from '../types/filament'
+import { useQuery } from '@tanstack/react-query'
+
+interface FilamentFormProps {
+  mode: 'create' | 'edit'
+  initialData?: FilamentSpool | null
+  onClose: () => void
+  onSuccess: () => void
+}
+
+interface FormErrors {
+  [key: string]: string
+}
+
+export default function FilamentForm({ mode, initialData, onClose, onSuccess }: FilamentFormProps) {
+  const [name, setName] = useState('')
+  const [materialBaseId, setMaterialBaseId] = useState('')
+  const [materialFinishId, setMaterialFinishId] = useState('1')
+  const [materialModifierId, setMaterialModifierId] = useState('')
+  const [colorHex, setColorHex] = useState('#3B82F6')
+  const [brand, setBrand] = useState('')
+  const [diameterMm, setDiameterMm] = useState('1.75')
+  const [initialGrams, setInitialGrams] = useState('')
+  const [remainingGrams, setRemainingGrams] = useState('')
+  const [costUsd, setCostUsd] = useState('')
+  const [lowStockThreshold, setLowStockThreshold] = useState('50')
+  const [notes, setNotes] = useState('')
+  const [barcode, setBarcode] = useState('')
+  const [errors, setErrors] = useState<FormErrors>({})
+  const [submitting, setSubmitting] = useState(false)
+  const [submitError, setSubmitError] = useState<string | null>(null)
+
+  const { data: materials } = useQuery({
+    queryKey: ['materials'],
+    queryFn: fetchMaterialBases,
+    staleTime: Infinity,
+  })
+  const { data: finishes } = useQuery({
+    queryKey: ['finishes'],
+    queryFn: fetchMaterialFinishes,
+    staleTime: Infinity,
+  })
+  const { data: modifiers } = useQuery({
+    queryKey: ['modifiers'],
+    queryFn: fetchMaterialModifiers,
+    staleTime: Infinity,
+  })
+
+  useEffect(() => {
+    if (mode === 'edit' && initialData) {
+      setName(initialData.name ?? '')
+      setMaterialBaseId(String(initialData.material_base_id ?? ''))
+      setMaterialFinishId(String(initialData.material_finish_id ?? '1'))
+      setMaterialModifierId(initialData.material_modifier_id ? String(initialData.material_modifier_id) : '')
+      setColorHex(initialData.color_hex ?? '#3B82F6')
+      setBrand(initialData.brand ?? '')
+      setDiameterMm(String(initialData.diameter_mm ?? 1.75))
+      setInitialGrams(String(initialData.initial_grams ?? ''))
+      setRemainingGrams(String(initialData.remaining_grams ?? ''))
+      setCostUsd(initialData.cost_usd != null ? String(initialData.cost_usd) : '')
+      setLowStockThreshold(String(initialData.low_stock_threshold_grams ?? 50))
+      setNotes(initialData.notes ?? '')
+      setBarcode(initialData.barcode ?? '')
+    }
+  }, [mode, initialData])
+
+  const colorHexValid = useMemo(() => {
+    return /^#[0-9A-Fa-f]{6}$/.test(colorHex)
+  }, [colorHex])
+
+  function validate(): FormErrors {
+    const e: FormErrors = {}
+    if (!name.trim()) e.name = 'Name is required'
+    if (!materialBaseId) e.material_base_id = 'Material Base is required'
+    if (!materialFinishId) e.material_finish_id = 'Material Finish is required'
+    if (!colorHexValid) e.color_hex = 'Enter a valid hex color (e.g., #FF0000)'
+    if (!initialGrams || Number(initialGrams) <= 0) e.initial_grams = 'Must be > 0'
+    if (remainingGrams === '' || Number(remainingGrams) < 0) e.remaining_grams = 'Must be >= 0'
+    if (Number(remainingGrams) > Number(initialGrams)) e.remaining_grams = 'Cannot exceed Initial Grams'
+    if (costUsd && Number(costUsd) < 0) e.cost_usd = 'Must be >= 0'
+    if (!diameterMm || Number(diameterMm) <= 0) e.diameter_mm = 'Must be > 0'
+    if (!lowStockThreshold || Number(lowStockThreshold) < 0) e.low_stock_threshold_grams = 'Must be >= 0'
+    return e
+  }
+
+  async function handleSubmit(e: React.FormEvent) {
+    e.preventDefault()
+    setSubmitError(null)
+    const validation = validate()
+    if (Object.keys(validation).length > 0) {
+      setErrors(validation)
+      return
+    }
+    setErrors({})
+    setSubmitting(true)
+
+    const payload: Record<string, unknown> = {
+      name: name.trim(),
+      material_base_id: Number(materialBaseId),
+      material_finish_id: Number(materialFinishId),
+      color_hex: colorHex,
+      initial_grams: Number(initialGrams),
+      remaining_grams: Number(remainingGrams),
+      diameter_mm: Number(diameterMm),
+      low_stock_threshold_grams: Number(lowStockThreshold),
+    }
+
+    if (materialModifierId) payload.material_modifier_id = Number(materialModifierId)
+    if (brand.trim()) payload.brand = brand.trim()
+    if (costUsd) payload.cost_usd = Number(costUsd)
+    if (notes.trim()) payload.notes = notes.trim()
+    if (barcode.trim()) payload.barcode = barcode.trim()
+
+    try {
+      if (mode === 'edit' && initialData) {
+        await updateFilament(initialData.id, payload)
+      } else {
+        await createFilament(payload)
+      }
+      onSuccess()
+      onClose()
+    } catch (err: any) {
+      setSubmitError(err?.response?.data?.error || 'Failed to save spool. Please try again.')
+    } finally {
+      setSubmitting(false)
+    }
+  }
+
+  return (
+    <div className="fixed inset-0 z-50 flex items-start justify-center sm:items-center bg-black/60 backdrop-blur-sm p-4 overflow-y-auto">
+      <div className="w-full max-w-2xl rounded-xl bg-slate-800 border border-slate-700 shadow-2xl overflow-hidden my-4">
+        {/* Header */}
+        <div className="flex items-center justify-between px-6 py-4 border-b border-slate-700">
+          <h3 className="text-lg font-semibold text-slate-100">
+            {mode === 'edit' ? 'Edit Filament Spool' : 'Add Filament Spool'}
+          </h3>
+          <button
+            onClick={onClose}
+            className="p-1.5 rounded-lg text-slate-400 hover:text-slate-100 hover:bg-slate-700 transition-colors"
+            type="button"
+            aria-label="Close"
+          >
+            <X size={18} />
+          </button>
+        </div>
+
+        {/* Error banner */}
+        {submitError && (
+          <div className="mx-6 mt-4 flex items-start gap-2 rounded-lg bg-red-900/30 border border-red-700 px-4 py-3 text-sm text-red-300">
+            <AlertCircle size={16} className="shrink-0 mt-0.5" />
+            <span>{submitError}</span>
+          </div>
+        )}
+
+        {/* Form */}
+        <form onSubmit={handleSubmit} className="px-6 py-4 space-y-5">
+          {/* Row 1: Name + Brand */}
+          <div className="grid grid-cols-1 sm:grid-cols-2 gap-4">
+            <div>
+              <label className="block text-sm font-medium text-slate-300 mb-1">Name <span className="text-red-400">*</span></label>
+              <input
+                type="text"
+                value={name}
+                onChange={e => setName(e.target.value)}
+                className={`w-full rounded-lg bg-slate-900 border px-3 py-2.5 text-sm text-slate-100 focus:outline-none focus:ring-2 ${errors.name ? 'border-red-500 focus:ring-red-500' : 'border-slate-600 focus:ring-emerald-500'}`}
+                placeholder="e.g. Sunlu PLA Silk Red"
+              />
+              {errors.name && <p className="mt-1 text-xs text-red-400">{errors.name}</p>}
+            </div>
+            <div>
+              <label className="block text-sm font-medium text-slate-300 mb-1">Brand</label>
+              <input
+                type="text"
+                value={brand}
+                onChange={e => setBrand(e.target.value)}
+                className="w-full rounded-lg bg-slate-900 border border-slate-600 px-3 py-2.5 text-sm text-slate-100 focus:outline-none focus:ring-2 focus:ring-emerald-500"
+                placeholder="e.g. Hatchbox"
+              />
+            </div>
+          </div>
+
+          {/* Row 2: Material Base + Finish + Modifier */}
+          <div className="grid grid-cols-1 sm:grid-cols-3 gap-4">
+            <div>
+              <label className="block text-sm font-medium text-slate-300 mb-1">Material Base <span className="text-red-400">*</span></label>
+              <select
+                value={materialBaseId}
+                onChange={e => setMaterialBaseId(e.target.value)}
+                className={`w-full rounded-lg bg-slate-900 border px-3 py-2.5 text-sm text-slate-100 focus:outline-none focus:ring-2 ${errors.material_base_id ? 'border-red-500 focus:ring-red-500' : 'border-slate-600 focus:ring-emerald-500'}`}
+              >
+                <option value="">Select…</option>
+                {materials?.map((m: MaterialBase) => (
+                  <option key={m.id} value={m.id}>{m.name}</option>
+                ))}
+              </select>
+              {errors.material_base_id && <p className="mt-1 text-xs text-red-400">{errors.material_base_id}</p>}
+            </div>
+            <div>
+              <label className="block text-sm font-medium text-slate-300 mb-1">Finish <span className="text-red-400">*</span></label>
+              <select
+                value={materialFinishId}
+                onChange={e => setMaterialFinishId(e.target.value)}
+                className={`w-full rounded-lg bg-slate-900 border px-3 py-2.5 text-sm text-slate-100 focus:outline-none focus:ring-2 ${errors.material_finish_id ? 'border-red-500 focus:ring-red-500' : 'border-slate-600 focus:ring-emerald-500'}`}
+              >
+                {finishes?.map((f: MaterialFinish) => (
+                  <option key={f.id} value={f.id}>{f.name}</option>
+                ))}
+              </select>
+              {errors.material_finish_id && <p className="mt-1 text-xs text-red-400">{errors.material_finish_id}</p>}
+            </div>
+            <div>
+              <label className="block text-sm font-medium text-slate-300 mb-1">Modifier</label>
+              <select
+                value={materialModifierId}
+                onChange={e => setMaterialModifierId(e.target.value)}
+                className="w-full rounded-lg bg-slate-900 border border-slate-600 px-3 py-2.5 text-sm text-slate-100 focus:outline-none focus:ring-2 focus:ring-emerald-500"
+              >
+                <option value="">None</option>
+                {modifiers?.map((m: MaterialModifier) => (
+                  <option key={m.id} value={m.id}>{m.name}</option>
+                ))}
+              </select>
+            </div>
+          </div>
+
+          {/* Row 3: Color + Diameter */}
+          <div className="grid grid-cols-1 sm:grid-cols-2 gap-4">
+            <div>
+              <label className="block text-sm font-medium text-slate-300 mb-1">Color <span className="text-red-400">*</span></label>
+              <div className="flex items-center gap-3">
+                <input
+                  type="color"
+                  value={colorHex}
+                  onChange={e => setColorHex(e.target.value)}
+                  className="h-10 w-14 rounded border border-slate-600 bg-slate-900 cursor-pointer"
+                />
+                <div className="flex-1">
+                  <input
+                    type="text"
+                    value={colorHex}
+                    onChange={e => setColorHex(e.target.value)}
+                    className={`w-full rounded-lg bg-slate-900 border px-3 py-2.5 text-sm text-slate-100 font-mono uppercase focus:outline-none focus:ring-2 ${errors.color_hex ? 'border-red-500 focus:ring-red-500' : 'border-slate-600 focus:ring-emerald-500'}`}
+                    placeholder="#FF0000"
+                    maxLength={7}
+                  />
+                </div>
+                <ColorSwatch colorHex={colorHex} size={32} />
+              </div>
+              {errors.color_hex && <p className="mt-1 text-xs text-red-400">{errors.color_hex}</p>}
+            </div>
+            <div>
+              <label className="block text-sm font-medium text-slate-300 mb-1">Diameter (mm) <span className="text-red-400">*</span></label>
+              <input
+                type="number"
+                step="0.01"
+                value={diameterMm}
+                onChange={e => setDiameterMm(e.target.value)}
+                className={`w-full rounded-lg bg-slate-900 border px-3 py-2.5 text-sm text-slate-100 focus:outline-none focus:ring-2 ${errors.diameter_mm ? 'border-red-500 focus:ring-red-500' : 'border-slate-600 focus:ring-emerald-500'}`}
+              />
+              {errors.diameter_mm && <p className="mt-1 text-xs text-red-400">{errors.diameter_mm}</p>}
+            </div>
+          </div>
+
+          {/* Row 4: Grams */}
+          <div className="grid grid-cols-1 sm:grid-cols-3 gap-4">
+            <div>
+              <label className="block text-sm font-medium text-slate-300 mb-1">Initial Grams <span className="text-red-400">*</span></label>
+              <input
+                type="number"
+                value={initialGrams}
+                onChange={e => setInitialGrams(e.target.value)}
+                className={`w-full rounded-lg bg-slate-900 border px-3 py-2.5 text-sm text-slate-100 focus:outline-none focus:ring-2 ${errors.initial_grams ? 'border-red-500 focus:ring-red-500' : 'border-slate-600 focus:ring-emerald-500'}`}
+              />
+              {errors.initial_grams && <p className="mt-1 text-xs text-red-400">{errors.initial_grams}</p>}
+            </div>
+            <div>
+              <label className="block text-sm font-medium text-slate-300 mb-1">Remaining Grams <span className="text-red-400">*</span></label>
+              <input
+                type="number"
+                value={remainingGrams}
+                onChange={e => setRemainingGrams(e.target.value)}
+                className={`w-full rounded-lg bg-slate-900 border px-3 py-2.5 text-sm text-slate-100 focus:outline-none focus:ring-2 ${errors.remaining_grams ? 'border-red-500 focus:ring-red-500' : 'border-slate-600 focus:ring-emerald-500'}`}
+              />
+              {errors.remaining_grams && <p className="mt-1 text-xs text-red-400">{errors.remaining_grams}</p>}
+            </div>
+            <div>
+              <label className="block text-sm font-medium text-slate-300 mb-1">Cost (USD)</label>
+              <input
+                type="number"
+                step="0.01"
+                value={costUsd}
+                onChange={e => setCostUsd(e.target.value)}
+                className={`w-full rounded-lg bg-slate-900 border px-3 py-2.5 text-sm text-slate-100 focus:outline-none focus:ring-2 ${errors.cost_usd ? 'border-red-500 focus:ring-red-500' : 'border-slate-600 focus:ring-emerald-500'}`}
+              />
+            </div>
+          </div>
+
+          {/* Row 5: Threshold + Barcode */}
+          <div className="grid grid-cols-1 sm:grid-cols-2 gap-4">
+            <div>
+              <label className="block text-sm font-medium text-slate-300 mb-1">Low Stock Threshold (g) <span className="text-red-400">*</span></label>
+              <input
+                type="number"
+                value={lowStockThreshold}
+                onChange={e => setLowStockThreshold(e.target.value)}
+                className={`w-full rounded-lg bg-slate-900 border px-3 py-2.5 text-sm text-slate-100 focus:outline-none focus:ring-2 ${errors.low_stock_threshold_grams ? 'border-red-500 focus:ring-red-500' : 'border-slate-600 focus:ring-emerald-500'}`}
+              />
+              {errors.low_stock_threshold_grams && <p className="mt-1 text-xs text-red-400">{errors.low_stock_threshold_grams}</p>}
+            </div>
+            <div>
+              <label className="block text-sm font-medium text-slate-300 mb-1">Barcode</label>
+              <input
+                type="text"
+                value={barcode}
+                onChange={e => setBarcode(e.target.value)}
+                className="w-full rounded-lg bg-slate-900 border border-slate-600 px-3 py-2.5 text-sm text-slate-100 focus:outline-none focus:ring-2 focus:ring-emerald-500"
+                placeholder="e.g. 123456789012"
+              />
+            </div>
+          </div>
+
+          {/* Notes */}
+          <div>
+            <label className="block text-sm font-medium text-slate-300 mb-1">Notes</label>
+            <textarea
+              rows={3}
+              value={notes}
+              onChange={e => setNotes(e.target.value)}
+              className="w-full rounded-lg bg-slate-900 border border-slate-600 px-3 py-2.5 text-sm text-slate-100 focus:outline-none focus:ring-2 focus:ring-emerald-500 resize-y"
+              placeholder="Print temperature tips, storage notes, etc."
+            />
+          </div>
+
+          {/* Footer actions */}
+          <div className="flex justify-end gap-3 pt-2">
+            <button
+              type="button"
+              onClick={onClose}
+              className="rounded-lg bg-slate-700 px-4 py-2.5 text-sm font-medium text-slate-200 hover:bg-slate-600 transition-colors"
+            >
+              Cancel
+            </button>
+            <button
+              type="submit"
+              disabled={submitting}
+              className="inline-flex items-center gap-2 rounded-lg bg-emerald-600 px-4 py-2.5 text-sm font-semibold text-white hover:bg-emerald-500 active:bg-emerald-700 disabled:opacity-50 transition-colors"
+            >
+              <Save size={16} />
+              {submitting ? 'Saving…' : mode === 'edit' ? 'Update Spool' : 'Create Spool'}
+            </button>
+          </div>
+        </form>
+      </div>
+    </div>
+  )
+}

frontend/src/components/LoadingSpinner.tsx

@@ -0,0 +1,8 @@
+export default function LoadingSpinner() {
+  return (
+    <div className="flex flex-col items-center gap-3">
+      <div className="w-10 h-10 border-4 border-emerald-500/30 border-t-emerald-400 rounded-full animate-spin" />
+      <p className="text-slate-400 text-sm">Loading dashboard…</p>
+    </div>
+  )
+}

frontend/src/components/RecentPrints.tsx

@@ -0,0 +1,76 @@
+import type { PrintJob } from '../types'
+import { Clock, FileText } from 'lucide-react'
+
+interface RecentPrintsProps {
+  jobs: PrintJob[]
+}
+
+export default function RecentPrints({ jobs }: RecentPrintsProps) {
+  if (jobs.length === 0) {
+    return (
+      <div className="rounded-xl border border-slate-700 bg-slate-800 p-6 text-center text-slate-400">
+        <FileText size={32} className="mx-auto mb-3 text-slate-500" />
+        <p>No recent print jobs</p>
+      </div>
+    )
+  }
+
+  const statusColor = (status: string) => {
+    switch (status.toLowerCase()) {
+      case 'completed': return 'text-emerald-400 bg-emerald-500/10'
+      case 'in_progress': return 'text-sky-400 bg-sky-500/10'
+      case 'failed': return 'text-red-400 bg-red-500/10'
+      default: return 'text-slate-400 bg-slate-500/10'
+    }
+  }
+
+  return (
+    <div className="rounded-xl border border-slate-700 bg-slate-800 overflow-hidden">
+      <div className="overflow-x-auto">
+        <table className="w-full text-left">
+          <thead>
+            <tr className="border-b border-slate-700">
+              <th className="px-4 py-3 text-sm font-medium text-slate-400">Name</th>
+              <th className="px-4 py-3 text-sm font-medium text-slate-400">Status</th>
+              <th className="px-4 py-3 text-sm font-medium text-slate-400">Duration</th>
+              <th className="px-4 py-3 text-sm font-medium text-slate-400">Filament</th>
+              <th className="px-4 py-3 text-sm font-medium text-slate-400">Cost</th>
+            </tr>
+          </thead>
+          <tbody>
+            {jobs.map((job) => (
+              <tr key={job.id} className="border-b border-slate-700/50 last:border-0 hover:bg-slate-700/30 transition-colors">
+                <td className="px-4 py-3 text-sm text-slate-100 font-medium">{job.name}</td>
+                <td className="px-4 py-3">
+                  <span className={`inline-flex items-center gap-1 px-2 py-1 rounded-full text-xs font-medium ${statusColor(job.status)}`}>
+                    {job.status}
+                  </span>
+                </td>
+                <td className="px-4 py-3 text-sm text-slate-300">
+                  <div className="flex items-center gap-1">
+                    <Clock size={14} />
+                    {formatDuration(job.duration_seconds)}
+                  </div>
+                </td>
+                <td className="px-4 py-3 text-sm text-slate-300">
+                  {job.filament_used_grams?.toFixed(1) ?? '-'} g
+                </td>
+                <td className="px-4 py-3 text-sm text-slate-300">
+                  ${job.cost_usd?.toFixed(2) ?? '-'}
+                </td>
+              </tr>
+            ))}
+          </tbody>
+        </table>
+      </div>
+    </div>
+  )
+}
+
+function formatDuration(seconds: number): string {
+  if (!seconds) return '-'
+  const hrs = Math.floor(seconds / 3600)
+  const mins = Math.floor((seconds % 3600) / 60)
+  if (hrs > 0) return `${hrs}h ${mins}m`
+  return `${mins}m`
+}

frontend/src/components/SummaryCard.tsx

@@ -0,0 +1,31 @@
+import type { LucideIcon } from 'lucide-react'
+
+interface SummaryCardProps {
+  title: string
+  value: string | number
+  icon: LucideIcon
+  color: 'emerald' | 'amber' | 'sky' | 'violet'
+}
+
+const colorMap = {
+  emerald: { bg: 'bg-emerald-500/10', border: 'border-emerald-500/20', text: 'text-emerald-400', icon: 'text-emerald-400' },
+  amber:   { bg: 'bg-amber-500/10',  border: 'border-amber-500/20',  text: 'text-amber-400',  icon: 'text-amber-400' },
+  sky:     { bg: 'bg-sky-500/10',    border: 'border-sky-500/20',    text: 'text-sky-400',    icon: 'text-sky-400' },
+  violet:  { bg: 'bg-violet-500/10', border: 'border-violet-500/20', text: 'text-violet-400', icon: 'text-violet-400' },
+}
+
+export default function SummaryCard({ title, value, icon: Icon, color }: SummaryCardProps) {
+  const c = colorMap[color]
+
+  return (
+    <div className={`rounded-xl border ${c.border} ${c.bg} p-5 flex items-start justify-between`}>
+      <div>
+        <p className="text-sm font-medium text-slate-400 mb-1">{title}</p>
+        <p className={`text-3xl font-bold ${c.text}`}>{value}</p>
+      </div>
+      <div className={`p-2 rounded-lg ${c.bg}`}>
+        <Icon size={24} className={c.icon} />
+      </div>
+    </div>
+  )
+}

frontend/src/environments/environment.prod.ts

@@ -1,8 +0,0 @@
-/**
- * Environment configuration for the Extrudex frontend (production).
- * Override API URL for deployed environments.
- */
-export const environment = {
-  production: true,
-  apiBaseUrl: '/api',
-};

frontend/src/environments/environment.ts

@@ -1,8 +0,0 @@
-/**
- * Environment configuration for the Extrudex frontend.
- * Replace API URL with the actual backend endpoint in production.
- */
-export const environment = {
-  production: false,
-  apiBaseUrl: 'http://localhost:5000',
-};

frontend/src/index.css

@@ -0,0 +1,8 @@
+@import "tailwindcss";
+
+body {
+  margin: 0;
+  min-height: 100vh;
+  background-color: #0f172a; /* slate-900 */
+  color: #f8fafc; /* slate-50 */
+}

frontend/src/index.html

@@ -1,20 +0,0 @@
-<!doctype html>
-<html lang="en">
-  <head>
-    <meta charset="utf-8" />
-    <title>Frontend</title>
-    <base href="/" />
-    <meta name="viewport" content="width=device-width, initial-scale=1" />
-    <link rel="icon" type="image/x-icon" href="favicon.ico" />
-    <link rel="preconnect" href="https://fonts.googleapis.com" />
-    <link rel="preconnect" href="https://fonts.gstatic.com" crossorigin />
-    <link
-      href="https://fonts.googleapis.com/css2?family=Roboto:wght@300;400;500&display=swap"
-      rel="stylesheet"
-    />
-    <link href="https://fonts.googleapis.com/icon?family=Material+Icons" rel="stylesheet" />
-  </head>
-  <body>
-    <app-root></app-root>
-  </body>
-</html>

frontend/src/main.ts

@@ -1,6 +0,0 @@
-import { bootstrapApplication } from '@angular/platform-browser';
-import { appConfig } from './app/app.config';
-import { App } from './app/app';
-
-bootstrapApplication(App, appConfig)
-  .catch((err) => console.error(err));

frontend/src/main.tsx

@@ -0,0 +1,25 @@
+import { StrictMode } from 'react'
+import { createRoot } from 'react-dom/client'
+import { QueryClient, QueryClientProvider } from '@tanstack/react-query'
+import { BrowserRouter } from 'react-router-dom'
+import './index.css'
+import App from './App'
+
+const queryClient = new QueryClient({
+  defaultOptions: {
+    queries: {
+      staleTime: 30_000,
+      refetchOnWindowFocus: false,
+    },
+  },
+})
+
+createRoot(document.getElementById('root')!).render(
+  <StrictMode>
+    <QueryClientProvider client={queryClient}>
+      <BrowserRouter>
+        <App />
+      </BrowserRouter>
+    </QueryClientProvider>
+  </StrictMode>,
+)

frontend/src/pages/Dashboard.tsx

@@ -0,0 +1,139 @@
+import { useQuery } from '@tanstack/react-query'
+import { getFilaments, getPrintJobs } from '../services/api'
+import SummaryCard from '../components/SummaryCard'
+import RecentPrints from '../components/RecentPrints'
+import LoadingSpinner from '../components/LoadingSpinner'
+import { Package, AlertTriangle, Printer, DollarSign, Plus, List } from 'lucide-react'
+
+export default function Dashboard() {
+  const {
+    data: filamentData,
+    isLoading: filamentLoading,
+    error: filamentError,
+  } = useQuery({
+    queryKey: ['filaments', 'count'],
+    queryFn: () => getFilaments({ limit: 1 }),
+  })
+
+  const {
+    data: lowStockData,
+    isLoading: lowStockLoading,
+    error: lowStockError,
+  } = useQuery({
+    queryKey: ['filaments', 'lowStock'],
+    queryFn: () => getFilaments({ low_stock: true, limit: 1 }),
+  })
+
+  const {
+    data: recentPrints,
+    isLoading: printsLoading,
+    error: printsError,
+  } = useQuery({
+    queryKey: ['printJobs', 'recent'],
+    queryFn: () => getPrintJobs({ limit: 5 }),
+  })
+
+  const {
+    data: allPrints,
+    isLoading: costLoading,
+    error: costError,
+  } = useQuery({
+    queryKey: ['printJobs', 'all'],
+    queryFn: () => getPrintJobs({ limit: 1000 }),
+  })
+
+  const totalSpools = filamentData?.total ?? 0
+  const lowStockCount = lowStockData?.total ?? 0
+  const recentPrintJobs = recentPrints?.data ?? []
+
+  // Calculate cost this month from all print jobs
+  const now = new Date()
+  const currentMonth = now.getMonth()
+  const currentYear = now.getFullYear()
+  const monthlyCost =
+    allPrints?.data
+      .filter((job) => {
+        const d = new Date(job.started_at)
+        return d.getMonth() === currentMonth && d.getFullYear() === currentYear
+      })
+      .reduce((sum, job) => sum + (job.cost_usd ?? 0), 0) ?? 0
+
+  const isLoading = filamentLoading || lowStockLoading || printsLoading || costLoading
+  const error = filamentError || lowStockError || printsError || costError
+
+  if (isLoading) {
+    return (
+      <div className="min-h-screen flex items-center justify-center bg-slate-900">
+        <LoadingSpinner />
+      </div>
+    )
+  }
+
+  if (error) {
+    return (
+      <div className="min-h-screen flex items-center justify-center bg-slate-900">
+        <div className="p-6 rounded-lg bg-red-900/30 border border-red-500 text-red-200 max-w-md">
+          <h2 className="text-xl font-bold mb-2">Error</h2>
+          <p className="text-sm">{(error as Error).message || 'Failed to load dashboard data.'}</p>
+        </div>
+      </div>
+    )
+  }
+
+  return (
+    <div className="min-h-screen bg-slate-900 p-4 md:p-8">
+      <div className="max-w-6xl mx-auto">
+        <header className="mb-8">
+          <h1 className="text-3xl font-bold text-emerald-400 mb-2">Dashboard</h1>
+          <p className="text-slate-400">Overview of your Extrudex inventory and prints</p>
+        </header>
+
+        {/* Summary Cards Grid */}
+        <div className="grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-4 gap-4 mb-8">
+          <SummaryCard
+            title="Total Spools"
+            value={totalSpools}
+            icon={Package}
+            color="emerald"
+          />
+          <SummaryCard
+            title="Low Stock"
+            value={lowStockCount}
+            icon={AlertTriangle}
+            color={lowStockCount > 0 ? 'amber' : 'emerald'}
+          />
+          <SummaryCard
+            title="Recent Prints"
+            value={recentPrintJobs.length}
+            icon={Printer}
+            color="sky"
+          />
+          <SummaryCard
+            title="Cost This Month"
+            value={`$${monthlyCost.toFixed(2)}`}
+            icon={DollarSign}
+            color="violet"
+          />
+        </div>
+
+        {/* Quick Actions */}
+        <div className="flex flex-wrap gap-3 mb-8">
+          <button className="flex items-center gap-2 px-4 py-2 rounded-lg bg-emerald-600 hover:bg-emerald-500 text-white font-medium transition-colors active:scale-95 touch-manipulation">
+            <Plus size={18} />
+            Add Spool
+          </button>
+          <button className="flex items-center gap-2 px-4 py-2 rounded-lg bg-slate-700 hover:bg-slate-600 text-slate-100 font-medium transition-colors active:scale-95 touch-manipulation">
+            <List size={18} />
+            View Inventory
+          </button>
+        </div>
+
+        {/* Recent Prints Section */}
+        <section>
+          <h2 className="text-xl font-semibold text-slate-100 mb-4">Recent Prints</h2>
+          <RecentPrints jobs={recentPrintJobs} />
+        </section>
+      </div>
+    </div>
+  )
+}

frontend/src/pages/InventoryPage.tsx

@@ -0,0 +1,363 @@
+import { useState, useMemo } from 'react'
+import { useQuery } from '@tanstack/react-query'
+import { Search, Filter, ChevronLeft, ChevronRight, Trash2, Pencil, Plus, AlertTriangle } from 'lucide-react'
+import ColorSwatch from '../components/ColorSwatch'
+import FilamentForm from '../components/FilamentForm'
+import { fetchFilaments, deleteFilament } from '../services/filamentService'
+import type { FilamentSpool, FilamentFilter } from '../types/filament'
+
+const PAGE_SIZE = 20
+
+type SortField = 'name' | 'remaining_grams' | 'cost_usd'
+type SortDir = 'asc' | 'desc'
+
+export default function InventoryPage() {
+  const [search, setSearch] = useState('')
+  const [material, setMaterial] = useState('')
+  const [finish, setFinish] = useState('')
+  const [lowStockOnly, setLowStockOnly] = useState(false)
+  const [sortBy, setSortBy] = useState<SortField>('name')
+  const [sortDir, setSortDir] = useState<SortDir>('asc')
+  const [page, setPage] = useState(0)
+  const [deleteId, setDeleteId] = useState<number | null>(null)
+  const [formOpen, setFormOpen] = useState(false)
+  const [formMode, setFormMode] = useState<'create' | 'edit'>('create')
+  const [formInitial, setFormInitial] = useState<FilamentSpool | null>(null)
+
+  const filter: FilamentFilter = useMemo(() => ({
+    material: material || undefined,
+    finish: finish || undefined,
+    low_stock: lowStockOnly,
+    sort_by: sortBy,
+    sort_dir: sortDir,
+    limit: PAGE_SIZE,
+    offset: page * PAGE_SIZE,
+  }), [material, finish, lowStockOnly, sortBy, sortDir, page])
+
+  const { data, isLoading, error, refetch } = useQuery({
+    queryKey: ['filaments', filter],
+    queryFn: () => fetchFilaments(filter),
+  })
+
+  const filaments = data?.data ?? []
+  const total = data?.total ?? 0
+  const totalPages = Math.max(1, Math.ceil(total / PAGE_SIZE))
+
+  // Client-side search filter (name/barcode) since backend may not support it yet.
+  const filtered = useMemo(() => {
+    if (!search.trim()) return filaments
+    const q = search.toLowerCase()
+    return filaments.filter(
+      (f: FilamentSpool) =>
+        f.name.toLowerCase().includes(q) ||
+        (f.barcode && f.barcode.toLowerCase().includes(q))
+    )
+  }, [filaments, search])
+
+  const handleSort = (field: SortField) => {
+    if (sortBy === field) {
+      setSortDir(prev => (prev === 'asc' ? 'desc' : 'asc'))
+    } else {
+      setSortBy(field)
+      setSortDir('asc')
+    }
+    setPage(0)
+  }
+
+  const handleDelete = async (id: number) => {
+    await deleteFilament(id)
+    setDeleteId(null)
+    refetch()
+  }
+
+  const SortIndicator = ({ field }: { field: SortField }) => {
+    if (sortBy !== field) return <span className="text-slate-600 ml-1">↕</span>
+    return <span className="text-emerald-400 ml-1">{sortDir === 'asc' ? '↑' : '↓'}</span>
+  }
+
+  return (
+    <div className="space-y-4">
+      {/* Header */}
+      <div className="flex flex-col sm:flex-row sm:items-center sm:justify-between gap-3">
+        <div>
+          <h2 className="text-xl font-bold text-slate-100">Filament Inventory</h2>
+          <p className="text-sm text-slate-400">{total} spool(s) total</p>
+        </div>
+        <button
+          onClick={() => { setFormMode('create'); setFormInitial(null); setFormOpen(true) }}
+          className="inline-flex items-center gap-2 rounded-lg bg-emerald-600 px-4 py-2 text-sm font-semibold text-white hover:bg-emerald-500 active:bg-emerald-700 transition-colors"
+        >
+          <Plus size={16} /> Add Spool
+        </button>
+      </div>
+
+      {/* Filters */}
+      <div className="flex flex-col lg:flex-row gap-3">
+        {/* Search */}
+        <div className="relative flex-1">
+          <Search size={16} className="absolute left-3 top-1/2 -translate-y-1/2 text-slate-400" />
+          <input
+            type="text"
+            placeholder="Search by name or barcode…"
+            value={search}
+            onChange={e => { setSearch(e.target.value); setPage(0) }}
+            className="w-full rounded-lg bg-slate-800 border border-slate-700 pl-9 pr-3 py-2 text-sm text-slate-100 placeholder-slate-500 focus:outline-none focus:ring-2 focus:ring-emerald-500 focus:border-emerald-500"
+          />
+        </div>
+
+        {/* Material filter */}
+        <select
+          value={material}
+          onChange={e => { setMaterial(e.target.value); setPage(0) }}
+          className="rounded-lg bg-slate-800 border border-slate-700 px-3 py-2 text-sm text-slate-100 focus:outline-none focus:ring-2 focus:ring-emerald-500"
+        >
+          <option value="">All Materials</option>
+          <option value="PLA">PLA</option>
+          <option value="PETG">PETG</option>
+          <option value="ABS">ABS</option>
+          <option value="TPU">TPU</option>
+          <option value="ASA">ASA</option>
+          <option value="Nylon">Nylon</option>
+          <option value="PC">PC</option>
+        </select>
+
+        {/* Finish filter */}
+        <select
+          value={finish}
+          onChange={e => { setFinish(e.target.value); setPage(0) }}
+          className="rounded-lg bg-slate-800 border border-slate-700 px-3 py-2 text-sm text-slate-100 focus:outline-none focus:ring-2 focus:ring-emerald-500"
+        >
+          <option value="">All Finishes</option>
+          <option value="Basic">Basic</option>
+          <option value="Silk">Silk</option>
+          <option value="Matte">Matte</option>
+          <option value="Glossy">Glossy</option>
+          <option value="Wood">Wood</option>
+          <option value="Marble">Marble</option>
+        </select>
+
+        {/* Low stock toggle */}
+        <label className="inline-flex items-center gap-2 rounded-lg bg-slate-800 border border-slate-700 px-3 py-2 text-sm text-slate-100 cursor-pointer select-none hover:bg-slate-750">
+          <Filter size={14} className="text-amber-400" />
+          <input
+            type="checkbox"
+            checked={lowStockOnly}
+            onChange={e => { setLowStockOnly(e.target.checked); setPage(0) }}
+            className="accent-amber-500"
+          />
+          Low Stock Only
+        </label>
+      </div>
+
+      {/* Loading / Error */}
+      {isLoading && (
+        <div className="text-center py-12 text-slate-400">Loading spools…</div>
+      )}
+      {error && (
+        <div className="text-center py-12 text-red-400">
+          Failed to load inventory.
+          <button onClick={() => refetch()} className="ml-2 underline hover:text-red-300">Retry</button>
+        </div>
+      )}
+
+      {/* Desktop Table */}
+      {!isLoading && !error && (
+        <>
+          <div className="hidden md:block overflow-x-auto rounded-lg border border-slate-700">
+            <table className="w-full text-sm">
+              <thead className="bg-slate-800 text-slate-300">
+                <tr>
+                  <th className="px-4 py-3 text-left font-semibold cursor-pointer select-none hover:text-slate-100" onClick={() => handleSort('name')}>
+                    Name <SortIndicator field="name" />
+                  </th>
+                  <th className="px-4 py-3 text-left font-semibold">Material</th>
+                  <th className="px-4 py-3 text-left font-semibold">Finish</th>
+                  <th className="px-4 py-3 text-left font-semibold">Color</th>
+                  <th className="px-4 py-3 text-right font-semibold cursor-pointer select-none hover:text-slate-100" onClick={() => handleSort('remaining_grams')}>
+                    Remaining <SortIndicator field="remaining_grams" />
+                  </th>
+                  <th className="px-4 py-3 text-right font-semibold cursor-pointer select-none hover:text-slate-100" onClick={() => handleSort('cost_usd')}>
+                    Cost <SortIndicator field="cost_usd" />
+                  </th>
+                  <th className="px-4 py-3 text-center font-semibold">Status</th>
+                  <th className="px-4 py-3 text-right font-semibold">Actions</th>
+                </tr>
+              </thead>
+              <tbody className="divide-y divide-slate-700">
+                {filtered.length === 0 && (
+                  <tr>
+                    <td colSpan={8} className="px-4 py-8 text-center text-slate-500">No spools found.</td>
+                  </tr>
+                )}
+                {filtered.map((spool: FilamentSpool) => {
+                  const isLow = spool.remaining_grams <= spool.low_stock_threshold_grams
+                  return (
+                    <tr key={spool.id} className={`${isLow ? 'bg-red-900/20' : 'bg-slate-800/50'} hover:bg-slate-700/50 transition-colors`}>
+                      <td className="px-4 py-3 font-medium text-slate-100">{spool.name}</td>
+                      <td className="px-4 py-3 text-slate-300">{spool.material_base?.name ?? '—'}</td>
+                      <td className="px-4 py-3 text-slate-300">{spool.material_finish?.name ?? '—'}</td>
+                      <td className="px-4 py-3">
+                        <div className="flex items-center gap-2">
+                          <ColorSwatch colorHex={spool.color_hex} size={20} />
+                          <span className="text-xs text-slate-400 uppercase">{spool.color_hex}</span>
+                        </div>
+                      </td>
+                      <td className="px-4 py-3 text-right tabular-nums text-slate-200">{spool.remaining_grams.toLocaleString()} g</td>
+                      <td className="px-4 py-3 text-right tabular-nums text-slate-300">{spool.cost_usd != null ? `$${spool.cost_usd.toFixed(2)}` : '—'}</td>
+                      <td className="px-4 py-3 text-center">
+                        {isLow ? (
+                          <span className="inline-flex items-center gap-1 rounded-full bg-red-900/50 border border-red-700 px-2 py-0.5 text-xs font-medium text-red-300">
+                            <AlertTriangle size={12} /> Low
+                          </span>
+                        ) : (
+                          <span className="inline-flex items-center rounded-full bg-emerald-900/30 border border-emerald-700 px-2 py-0.5 text-xs font-medium text-emerald-300">OK</span>
+                        )}
+                      </td>
+                      <td className="px-4 py-3 text-right">
+                        <div className="flex items-center justify-end gap-2">
+                          <button
+                            onClick={() => { setFormMode('edit'); setFormInitial(spool); setFormOpen(true) }}
+                            className="p-1.5 rounded hover:bg-slate-600 text-slate-400 hover:text-blue-400 transition-colors"
+                            title="Edit"
+                          >
+                            <Pencil size={14} />
+                          </button>
+                          <button
+                            onClick={() => setDeleteId(spool.id)}
+                            className="p-1.5 rounded hover:bg-slate-600 text-slate-400 hover:text-red-400 transition-colors"
+                            title="Delete"
+                          >
+                            <Trash2 size={14} />
+                          </button>
+                        </div>
+                      </td>
+                    </tr>
+                  )
+                })}
+              </tbody>
+            </table>
+          </div>
+
+          {/* Mobile Cards */}
+          <div className="md:hidden space-y-3">
+            {filtered.length === 0 && (
+              <div className="text-center py-12 text-slate-500">No spools found.</div>
+            )}
+            {filtered.map((spool: FilamentSpool) => {
+              const isLow = spool.remaining_grams <= spool.low_stock_threshold_grams
+              return (
+                <div key={spool.id} className={`rounded-lg border ${isLow ? 'border-red-700 bg-red-900/10' : 'border-slate-700 bg-slate-800'} p-4 space-y-2`}>
+                  <div className="flex items-start justify-between">
+                    <div>
+                      <div className="font-semibold text-slate-100">{spool.name}</div>
+                      <div className="text-xs text-slate-400 mt-0.5">{spool.material_base?.name ?? '—'} · {spool.material_finish?.name ?? '—'}</div>
+                    </div>
+                    {isLow ? (
+                      <span className="inline-flex items-center gap-1 rounded-full bg-red-900/50 border border-red-700 px-2 py-0.5 text-xs font-medium text-red-300">
+                        <AlertTriangle size={12} /> Low
+                      </span>
+                    ) : (
+                      <span className="inline-flex items-center rounded-full bg-emerald-900/30 border border-emerald-700 px-2 py-0.5 text-xs font-medium text-emerald-300">OK</span>
+                    )}
+                  </div>
+
+                  <div className="flex items-center gap-3 text-sm">
+                    <div className="flex items-center gap-2">
+                      <ColorSwatch colorHex={spool.color_hex} size={20} />
+                      <span className="text-slate-400 uppercase text-xs">{spool.color_hex}</span>
+                    </div>
+                  </div>
+
+                  <div className="flex items-center justify-between text-sm">
+                    <span className="text-slate-400">Remaining: <span className="text-slate-200 font-medium tabular-nums">{spool.remaining_grams.toLocaleString()} g</span></span>
+                    <span className="text-slate-400">{spool.cost_usd != null ? `$${spool.cost_usd.toFixed(2)}` : '—'}</span>
+                  </div>
+
+                  <div className="flex items-center justify-end gap-2 pt-1">
+                    <button
+                      onClick={() => { setFormMode('edit'); setFormInitial(spool); setFormOpen(true) }}
+                      className="flex items-center gap-1 rounded-md bg-slate-700 px-3 py-1.5 text-xs font-medium text-slate-200 hover:bg-slate-600"
+                    >
+                      <Pencil size={12} /> Edit
+                    </button>
+                    <button
+                      onClick={() => setDeleteId(spool.id)}
+                      className="flex items-center gap-1 rounded-md bg-red-900/30 border border-red-700 px-3 py-1.5 text-xs font-medium text-red-300 hover:bg-red-900/50"
+                    >
+                      <Trash2 size={12} /> Delete
+                    </button>
+                  </div>
+                </div>
+              )
+            })}
+          </div>
+
+          {/* Pagination */}
+          <div className="flex items-center justify-between pt-2">
+            <span className="text-sm text-slate-400">
+              Showing {page * PAGE_SIZE + 1}–{Math.min((page + 1) * PAGE_SIZE, total)} of {total}
+            </span>
+            <div className="flex items-center gap-2">
+              <button
+                onClick={() => setPage(p => Math.max(0, p - 1))}
+                disabled={page === 0}
+                className="p-2 rounded-lg bg-slate-800 border border-slate-700 text-slate-300 hover:bg-slate-700 disabled:opacity-40 disabled:cursor-not-allowed transition-colors"
+              >
+                <ChevronLeft size={16} />
+              </button>
+              <span className="text-sm text-slate-300 tabular-nums">{page + 1} / {totalPages}</span>
+              <button
+                onClick={() => setPage(p => Math.min(totalPages - 1, p + 1))}
+                disabled={page >= totalPages - 1}
+                className="p-2 rounded-lg bg-slate-800 border border-slate-700 text-slate-300 hover:bg-slate-700 disabled:opacity-40 disabled:cursor-not-allowed transition-colors"
+              >
+                <ChevronRight size={16} />
+              </button>
+            </div>
+          </div>
+        </>
+      )}
+
+      {/* Add/Edit Form Modal */}
+      {formOpen && (
+        <FilamentForm
+          mode={formMode}
+          initialData={formInitial}
+          onClose={() => setFormOpen(false)}
+          onSuccess={() => refetch()}
+        />
+      )}
+
+      {/* Delete confirmation modal */}
+      {deleteId !== null && (
+        <div className="fixed inset-0 z-50 flex items-center justify-center bg-black/60 backdrop-blur-sm p-4">
+          <div className="w-full max-w-sm rounded-xl bg-slate-800 border border-slate-700 p-6 shadow-2xl space-y-4">
+            <div className="flex items-center gap-3">
+              <div className="flex h-10 w-10 items-center justify-center rounded-full bg-red-900/30">
+                <AlertTriangle size={20} className="text-red-400" />
+              </div>
+              <div>
+                <h3 className="text-lg font-semibold text-slate-100">Delete Spool?</h3>
+                <p className="text-sm text-slate-400">This action cannot be undone.</p>
+              </div>
+            </div>
+            <div className="flex justify-end gap-3">
+              <button
+                onClick={() => setDeleteId(null)}
+                className="rounded-lg bg-slate-700 px-4 py-2 text-sm font-medium text-slate-200 hover:bg-slate-600 transition-colors"
+              >
+                Cancel
+              </button>
+              <button
+                onClick={() => handleDelete(deleteId)}
+                className="rounded-lg bg-red-600 px-4 py-2 text-sm font-medium text-white hover:bg-red-500 transition-colors"
+              >
+                Delete
+              </button>
+            </div>
+          </div>
+        </div>
+      )}
+    </div>
+  )
+}