feat(CUB-28): [Extrudex] Define filament inventory database entities

Add storage_location and is_archived fields to Spool entity to complete
the filament inventory entity definition per CUB-28 requirements.

Changes:
- Spool entity: add IsArchived (bool, default false) and StorageLocation
  (nullable string, max 200) for physical inventory tracking
- SpoolConfiguration: add snake_case column mappings, defaults, and indexes
  (ix_spools_is_archived, ix_spools_active_archived composite)
- FilamentDtos: add IsArchived + StorageLocation to Response, Create, Update
- FilamentQueryDtos: add IncludeArchived and StorageLocation query filters
- FilamentsController: wire new fields into query, create, update, mapping
- FilamentValidators: add StorageLocation max-length validation

Build: PASS (0 errors)

backend/API/Controllers/FilamentsController.cs

@@ -46,9 +46,11 @@ public class FilamentsController : ControllerBase
         _logger.LogDebug(
             "Getting filaments: pageNumber={PageNumber}, pageSize={PageSize}, " +
             "materialBaseId={MaterialBaseId}, materialFinishId={MaterialFinishId}, " +
-            "materialModifierId={MaterialModifierId}, brand={Brand}, isActive={IsActive}",
+            "materialModifierId={MaterialModifierId}, brand={Brand}, isActive={IsActive}, " +
+            "includeArchived={IncludeArchived}, storageLocation={StorageLocation}",
             query.PageNumber, query.PageSize, query.MaterialBaseId,
-            query.MaterialFinishId, query.MaterialModifierId, query.Brand, query.IsActive);
+            query.MaterialFinishId, query.MaterialModifierId, query.Brand, query.IsActive,
+            query.IncludeArchived, query.StorageLocation);
 
         // Clamp pagination values
         var pageNumber = Math.Max(1, query.PageNumber);
@@ -77,6 +79,15 @@ public class FilamentsController : ControllerBase
         if (query.IsActive.HasValue)
             spoolQuery = spoolQuery.Where(s => s.IsActive == query.IsActive.Value);
 
+        // Exclude archived spools by default; include when explicitly requested
+        if (query.IncludeArchived != true)
+            spoolQuery = spoolQuery.Where(s => !s.IsArchived);
+
+        if (!string.IsNullOrWhiteSpace(query.StorageLocation))
+            spoolQuery = spoolQuery.Where(s =>
+                s.StorageLocation != null &&
+                s.StorageLocation.ToLower().Contains(query.StorageLocation.ToLower()));
+
         var totalCount = await spoolQuery.CountAsync();
 
         var items = await spoolQuery
@@ -185,7 +196,9 @@ public class FilamentsController : ControllerBase
             SpoolSerial = request.SpoolSerial,
             PurchasePrice = request.PurchasePrice,
             PurchaseDate = request.PurchaseDate,
-            IsActive = request.IsActive
+            IsActive = request.IsActive,
+            IsArchived = request.IsArchived,
+            StorageLocation = request.StorageLocation
         };
 
         _dbContext.Spools.Add(entity);
@@ -267,6 +280,8 @@ public class FilamentsController : ControllerBase
         entity.PurchasePrice = request.PurchasePrice;
         entity.PurchaseDate = request.PurchaseDate;
         entity.IsActive = request.IsActive;
+        entity.IsArchived = request.IsArchived;
+        entity.StorageLocation = request.StorageLocation;
 
         await _dbContext.SaveChangesAsync();
 
@@ -307,6 +322,8 @@ public class FilamentsController : ControllerBase
         PurchasePrice = s.PurchasePrice,
         PurchaseDate = s.PurchaseDate,
         IsActive = s.IsActive,
+        IsArchived = s.IsArchived,
+        StorageLocation = s.StorageLocation,
         CreatedAt = s.CreatedAt,
         UpdatedAt = s.UpdatedAt,
         QrCodeUrl = $"/api/qr/spool/{s.Id}"

backend/API/DTOs/Filaments/FilamentDtos.cs

@@ -59,6 +59,12 @@ public class FilamentResponse
     /// <summary>Whether the spool is currently active and available.</summary>
     public bool IsActive { get; set; }
 
+    /// <summary>Whether the spool has been archived (removed from active inventory).</summary>
+    public bool IsArchived { get; set; }
+
+    /// <summary>Physical storage location (e.g., "Shelf A", "Drawer 3"). Null if unset.</summary>
+    public string? StorageLocation { get; set; }
+
     /// <summary>Timestamp when this record was created (UTC).</summary>
     public DateTime CreatedAt { get; set; }
 
@@ -133,6 +139,15 @@ public class CreateFilamentRequest
 
     /// <summary>Whether the spool is active. Defaults to true.</summary>
     public bool IsActive { get; set; } = true;
+
+    /// <summary>Whether the spool is archived. Defaults to false.
+    /// </summary>
+    public bool IsArchived { get; set; } = false;
+
+    /// <summary>Physical storage location (e.g., "Shelf A", "Drawer 3"). Optional.
+    /// </summary>
+    [StringLength(200, ErrorMessage = "StorageLocation must not exceed 200 characters.")]
+    public string? StorageLocation { get; set; }
 }
 
 /// <summary>
@@ -196,4 +211,11 @@ public class UpdateFilamentRequest
 
     /// <summary>Whether the spool is active.</summary>
     public bool IsActive { get; set; } = true;
+
+    /// <summary>Whether the spool is archived. Defaults to false.</summary>
+    public bool IsArchived { get; set; } = false;
+
+    /// <summary>Physical storage location (e.g., "Shelf A", "Drawer 3"). Optional.</summary>
+    [StringLength(200, ErrorMessage = "StorageLocation must not exceed 200 characters.")]
+    public string? StorageLocation { get; set; }
 }

backend/API/DTOs/Filaments/FilamentQueryDtos.cs

@@ -30,4 +30,11 @@ public class FilamentQueryParameters
 
     /// <summary>Optional filter by active status. True = active only, False = inactive only.</summary>
     public bool? IsActive { get; set; }
+
+    /// <summary>Whether to include archived spools in results. Defaults to false (excludes archived).
+    /// </summary>
+    public bool? IncludeArchived { get; set; }
+
+    /// <summary>Optional filter by storage location (case-insensitive partial match).</summary>
+    public string? StorageLocation { get; set; }
 }

backend/API/Validators/FilamentValidators.cs

@@ -52,6 +52,12 @@ public class CreateFilamentRequestValidator : AbstractValidator<CreateFilamentRe
             RuleFor(x => x.PurchasePrice!.Value)
                 .GreaterThanOrEqualTo(0).WithMessage("Purchase price must be non-negative.");
         });
+
+        When(x => x.StorageLocation != null, () =>
+        {
+            RuleFor(x => x.StorageLocation!)
+                .MaximumLength(200).WithMessage("StorageLocation must not exceed 200 characters.");
+        });
     }
 }
 
@@ -104,5 +110,11 @@ public class UpdateFilamentRequestValidator : AbstractValidator<UpdateFilamentRe
             RuleFor(x => x.PurchasePrice!.Value)
                 .GreaterThanOrEqualTo(0).WithMessage("Purchase price must be non-negative.");
         });
+
+        When(x => x.StorageLocation != null, () =>
+        {
+            RuleFor(x => x.StorageLocation!)
+                .MaximumLength(200).WithMessage("StorageLocation must not exceed 200 characters.");
+        });
     }
 }

backend/Domain/Entities/Spool.cs

@@ -93,6 +93,20 @@ public class Spool : AuditableEntity
     /// </summary>
     public bool IsActive { get; set; } = true;
 
+    /// <summary>
+    /// Whether the spool has been archived (removed from active inventory).
+    /// Archived spools are retained for historical records but hidden from
+    /// default inventory views. Distinguishes long-term archival from
+    /// temporary inactivity (e.g., spool swapped out of AMS).
+    /// </summary>
+    public bool IsArchived { get; set; } = false;
+
+    /// <summary>
+    /// Physical storage location of the spool (e.g., "Shelf A", "Drawer 3", "AMS Tray 2").
+    /// Optional — not every spool has a designated storage location.
+    /// </summary>
+    public string? StorageLocation { get; set; }
+
     /// <summary>
     /// Navigation collection of AMS slots where this spool is loaded.
     /// </summary>

backend/Infrastructure/Data/Configurations/SpoolConfiguration.cs

@@ -68,6 +68,15 @@ public class SpoolConfiguration : BaseEntityConfiguration<Spool>
             .HasDefaultValue(true)
             .IsRequired();
 
+        builder.Property(e => e.IsArchived)
+            .HasColumnName("is_archived")
+            .HasDefaultValue(false)
+            .IsRequired();
+
+        builder.Property(e => e.StorageLocation)
+            .HasColumnName("storage_location")
+            .HasMaxLength(200);
+
         // Unique index on spool_serial — critical for barcode/QR scanning
         builder.HasIndex(e => e.SpoolSerial)
             .IsUnique()
@@ -89,6 +98,14 @@ public class SpoolConfiguration : BaseEntityConfiguration<Spool>
         builder.HasIndex(e => e.IsActive)
             .HasDatabaseName("ix_spools_is_active");
 
+        // Index on is_archived for inventory filtering (exclude archived from default views)
+        builder.HasIndex(e => e.IsArchived)
+            .HasDatabaseName("ix_spools_is_archived");
+
+        // Composite index on is_active + is_archived for common inventory queries
+        builder.HasIndex(e => new { e.IsActive, e.IsArchived })
+            .HasDatabaseName("ix_spools_active_archived");
+
         // Relationships
         builder.HasOne(e => e.MaterialBase)
             .WithMany(e => e.Spools)