Merge pull request 'feat(CUB-55): SignalR Broadcast State Method' (#3) from agent/dex/CUB-55-signalr-broadcast into dev

Reviewed-on: #3
Reviewed-by: Joshua <joshua@cnjmail.com>

backend/.gitignore

@@ -0,0 +1,21 @@
+## .NET
+bin/
+obj/
+*.user
+*.suo
+*.cache
+*.dll
+*.pdb
+
+## IDE
+.vs/
+.idea/
+*.swp
+*~
+
+## OS
+.DS_Store
+Thumbs.db
+
+## Environment
+.env

backend/Configurations/AgentConfiguration.cs

@@ -0,0 +1,88 @@
+using ControlCenter.Api.Entities;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Metadata.Builders;
+
+namespace ControlCenter.Api.Configurations;
+
+/// <summary>
+/// EF Core entity type configuration for the agents table.
+/// Enforces snake_case naming, required fields, and index design.
+/// </summary>
+public class AgentConfiguration : IEntityTypeConfiguration<Agent>
+{
+    public void Configure(EntityTypeBuilder<Agent> builder)
+    {
+        // Table name — snake_case
+        builder.ToTable("agents");
+
+        // Primary key
+        builder.HasKey(a => a.Id);
+        builder.Property(a => a.Id)
+            .HasColumnName("id")
+            .ValueGeneratedOnAdd();
+
+        // Status — stored as PostgreSQL enum via Npgsql
+        builder.Property(a => a.Status)
+            .HasColumnName("status")
+            .HasColumnType("agent_status")
+            .IsRequired();
+
+        // Task — nullable text
+        builder.Property(a => a.Task)
+            .HasColumnName("task")
+            .HasColumnType("text");
+
+        // Progress — nullable integer (0–100)
+        builder.Property(a => a.Progress)
+            .HasColumnName("progress");
+
+        // Session key — required, not null
+        builder.Property(a => a.SessionKey)
+            .HasColumnName("session_key")
+            .HasColumnType("text")
+            .IsRequired();
+
+        // Channel — required, not null
+        builder.Property(a => a.Channel)
+            .HasColumnName("channel")
+            .HasColumnType("text")
+            .IsRequired();
+
+        // Last activity — required, defaults to now()
+        builder.Property(a => a.LastActivity)
+            .HasColumnName("last_activity")
+            .HasColumnType("timestamptz")
+            .IsRequired();
+
+        // Created at — auto-set on insert
+        builder.Property(a => a.CreatedAt)
+            .HasColumnName("created_at")
+            .HasColumnType("timestamptz")
+            .IsRequired()
+            .HasDefaultValueSql("now()");
+
+        // Updated at — auto-set on insert and update
+        builder.Property(a => a.UpdatedAt)
+            .HasColumnName("updated_at")
+            .HasColumnType("timestamptz")
+            .IsRequired()
+            .HasDefaultValueSql("now()");
+
+        // Indexes
+        // Sessions are looked up by session_key frequently
+        builder.HasIndex(a => a.SessionKey)
+            .HasDatabaseName("ix_agents_session_key")
+            .IsUnique();
+
+        // Agents are filtered by channel for channel-specific queries
+        builder.HasIndex(a => a.Channel)
+            .HasDatabaseName("ix_agents_channel");
+
+        // Agents are filtered by status for fleet health monitoring
+        builder.HasIndex(a => a.Status)
+            .HasDatabaseName("ix_agents_status");
+
+        // Check constraint: progress must be 0–100 if present
+        builder.ToTable(t => t.HasCheckConstraint("ck_agents_progress_range", "progress IS NULL OR (progress >= 0 AND progress <= 100)"));
+    }
+}

backend/ControlCenter.Api.csproj

@@ -0,0 +1,18 @@
+<Project Sdk="Microsoft.NET.Sdk.Web">
+
+  <PropertyGroup>
+    <TargetFramework>net9.0</TargetFramework>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.AspNetCore.OpenApi" Version="9.0.14" />
+    <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="9.0.4">
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+    <PackageReference Include="Npgsql.EntityFrameworkCore.PostgreSQL" Version="9.0.4" />
+  </ItemGroup>
+
+</Project>

backend/ControlCenter.Api.http

@@ -0,0 +1,6 @@
+@ControlCenter.Api_HostAddress = http://localhost:5178
+
+GET {{ControlCenter.Api_HostAddress}}/weatherforecast/
+Accept: application/json
+
+###

backend/Data/AppDbContext.cs

@@ -0,0 +1,29 @@
+using ControlCenter.Api.Configurations;
+using ControlCenter.Api.Entities;
+using Microsoft.EntityFrameworkCore;
+
+namespace ControlCenter.Api.Data;
+
+/// <summary>
+/// EF Core DbContext for the Control Center database.
+/// All table and column names use snake_case via explicit HasColumnName configuration.
+/// </summary>
+public class AppDbContext : DbContext
+{
+    public AppDbContext(DbContextOptions<AppDbContext> options) : base(options) { }
+
+    public DbSet<Agent> Agents => Set<Agent>();
+
+    protected override void OnModelCreating(ModelBuilder modelBuilder)
+    {
+        // Apply all entity type configurations from the Configurations namespace
+        modelBuilder.ApplyConfigurationsFromAssembly(typeof(AgentConfiguration).Assembly);
+
+        // Map the AgentStatus enum to a PostgreSQL enum type named "agent_status"
+        // This must be called after ApplyConfigurations to ensure the model is built
+        // before the enum mapping is applied.
+        modelBuilder.HasPostgresEnum<AgentStatus>();
+
+        base.OnModelCreating(modelBuilder);
+    }
+}

backend/Data/AppDbContextFactory.cs

@@ -0,0 +1,27 @@
+using Microsoft.EntityFrameworkCore;
+using ControlCenter.Api.Entities;
+
+namespace ControlCenter.Api.Data;
+
+/// <summary>
+/// Design-time factory for AppDbContext, used by EF Core tools (dotnet ef)
+/// to create migrations without requiring a running application.
+/// </summary>
+public class AppDbContextFactory : Microsoft.EntityFrameworkCore.Design.IDesignTimeDbContextFactory<AppDbContext>
+{
+    public AppDbContext CreateDbContext(string[] args)
+    {
+        var optionsBuilder = new DbContextOptionsBuilder<AppDbContext>();
+
+        // Connection string for design-time operations (migrations).
+        // In production, this comes from appsettings / environment variables.
+        var connectionString = "Host=localhost;Database=control_center;Username=postgres;Password=postgres";
+
+        optionsBuilder.UseNpgsql(connectionString, npgsqlOptions =>
+        {
+            npgsqlOptions.MigrationsAssembly(typeof(AppDbContext).Assembly.FullName);
+        });
+
+        return new AppDbContext(optionsBuilder.Options);
+    }
+}

backend/Dtos/AgentStatusUpdateDto.cs

@@ -0,0 +1,75 @@
+namespace ControlCenter.Api.Dtos;
+
+/// <summary>
+/// Data transfer object for broadcasting agent status updates
+/// to all connected SignalR clients.
+/// </summary>
+public class AgentStatusUpdateDto
+{
+    /// <summary>
+    /// Agent identifier, e.g. "otto", "dex", "rex".
+    /// Not null — every update must identify the agent it refers to.
+    /// </summary>
+    public string AgentId { get; set; } = string.Empty;
+
+    /// <summary>
+    /// Human-readable display name, e.g. "Otto", "Dex".
+    /// Not null — used by clients to render agent cards.
+    /// </summary>
+    public string DisplayName { get; set; } = string.Empty;
+
+    /// <summary>
+    /// Role description, e.g. "Orchestrator Agent", "Backend Specialist".
+    /// Not null — provides context for the agent's function.
+    /// </summary>
+    public string Role { get; set; } = string.Empty;
+
+    /// <summary>
+    /// Current operational status of the agent.
+    /// Maps to <see cref="Entities.AgentStatus"/> values as lowercase strings:
+    /// "active", "idle", "thinking", "error".
+    /// </summary>
+    public string Status { get; set; } = string.Empty;
+
+    /// <summary>
+    /// Description of the agent's current task, if any.
+    /// Null when the agent is idle with no active task.
+    /// </summary>
+    public string? CurrentTask { get; set; }
+
+    /// <summary>
+    /// Task progress percentage (0–100).
+    /// Null when progress is not trackable for the current task.
+    /// </summary>
+    public int? TaskProgress { get; set; }
+
+    /// <summary>
+    /// Elapsed time string for the current task, e.g. "04m 12s".
+    /// Null when no task is active.
+    /// </summary>
+    public string? TaskElapsed { get; set; }
+
+    /// <summary>
+    /// Full session key, e.g. "agent:otto:telegram:direct:8787451565".
+    /// Not null — uniquely identifies the agent session.
+    /// </summary>
+    public string SessionKey { get; set; } = string.Empty;
+
+    /// <summary>
+    /// Communication channel the agent is operating on, e.g. "telegram", "discord", "slack".
+    /// Not null — every agent session operates on exactly one channel.
+    /// </summary>
+    public string Channel { get; set; } = string.Empty;
+
+    /// <summary>
+    /// ISO 8601 timestamp of the agent's last activity.
+    /// Not null — used by clients to detect stale connections.
+    /// </summary>
+    public string LastActivity { get; set; } = string.Empty;
+
+    /// <summary>
+    /// Error message when the agent status is "error".
+    /// Null when the agent is not in an error state.
+    /// </summary>
+    public string? ErrorMessage { get; set; }
+}

backend/Entities/Agent.cs

@@ -0,0 +1,59 @@
+namespace ControlCenter.Api.Entities;
+
+/// <summary>
+/// Represents an agent's current state in the Control Center.
+/// Each row tracks one agent session's status, task, and activity.
+/// </summary>
+public class Agent
+{
+    /// <summary>
+    /// Primary key — UUID generated on insert.
+    /// </summary>
+    public Guid Id { get; set; }
+
+    /// <summary>
+    /// Current operational status of the agent.
+    /// Stored as an enum in PostgreSQL via Npgsql.
+    /// </summary>
+    public AgentStatus Status { get; set; } = AgentStatus.Idle;
+
+    /// <summary>
+    /// Description of the agent's current task, if any.
+    /// Nullable — not all agents have an active task.
+    /// </summary>
+    public string? Task { get; set; }
+
+    /// <summary>
+    /// Task progress percentage (0–100).
+    /// Nullable — progress is only meaningful when an agent has a trackable task.
+    /// </summary>
+    public int? Progress { get; set; }
+
+    /// <summary>
+    /// Full session key, e.g. "agent:otto:telegram:direct:8787451565".
+    /// Not null — every agent row must be associated with a session.
+    /// </summary>
+    public string SessionKey { get; set; } = string.Empty;
+
+    /// <summary>
+    /// Communication channel the agent is operating on, e.g. "telegram", "discord", "slack".
+    /// Not null — every agent session operates on exactly one channel.
+    /// </summary>
+    public string Channel { get; set; } = string.Empty;
+
+    /// <summary>
+    /// Timestamp of the agent's last activity.
+    /// Default: current UTC timestamp on insert.
+    /// </summary>
+    public DateTime LastActivity { get; set; } = DateTime.UtcNow;
+
+    /// <summary>
+    /// Row creation timestamp. Set automatically on insert.
+    /// </summary>
+    public DateTime CreatedAt { get; set; } = DateTime.UtcNow;
+
+    /// <summary>
+    /// Row last-update timestamp. Updated automatically on any modification.
+    /// </summary>
+    public DateTime UpdatedAt { get; set; } = DateTime.UtcNow;
+}

backend/Entities/AgentStatus.cs

@@ -0,0 +1,13 @@
+namespace ControlCenter.Api.Entities;
+
+/// <summary>
+/// Agent operational status enum.
+/// Maps to the agent_status enum type in PostgreSQL.
+/// </summary>
+public enum AgentStatus
+{
+    Active = 0,
+    Idle = 1,
+    Thinking = 2,
+    Error = 3
+}

backend/Hubs/AgentStatusHub.cs

@@ -0,0 +1,155 @@
+using ControlCenter.Api.Dtos;
+using Microsoft.AspNetCore.SignalR;
+
+namespace ControlCenter.Api.Hubs;
+
+/// <summary>
+/// SignalR hub for broadcasting agent status updates to connected clients.
+///
+/// <para>
+/// Clients call <see cref="SendStatusUpdate"/> to broadcast a status change,
+/// and the hub relays it to all connected clients via the
+/// <see cref="IAgentStatusClient.AgentStatusChanged"/> callback.
+/// </para>
+///
+/// <para>
+/// Server-side code should use <see cref="AgentStatusHubExtensions.PushStatusUpdateAsync"/>
+/// via <c>IHubContext&lt;AgentStatusHub, IAgentStatusClient&gt;</c> for background-service broadcasts.
+/// </para>
+///
+/// <para>
+/// Architecture note: This hub bridges OpenClaw Gateway events to SignalR clients.
+/// A background service subscribes to Gateway events and pushes them through
+/// this hub's extension methods.
+/// </para>
+/// </summary>
+public class AgentStatusHub : Hub<IAgentStatusClient>
+{
+    private readonly ILogger<AgentStatusHub> _logger;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="AgentStatusHub"/> class.
+    /// </summary>
+    /// <param name="logger">Logger for diagnostic output.</param>
+    public AgentStatusHub(ILogger<AgentStatusHub> logger)
+    {
+        _logger = logger;
+    }
+
+    /// <summary>
+    /// Broadcasts an agent status update to all connected clients.
+    ///
+    /// <para>
+    /// Any connected client (or server-side caller) can invoke this method
+    /// to push a status update to every subscriber. The update is relayed
+    /// through the <see cref="IAgentStatusClient.AgentStatusChanged"/> callback.
+    /// </para>
+    /// </summary>
+    /// <param name="update">The agent status update payload to broadcast.</param>
+    public async Task SendStatusUpdate(AgentStatusUpdateDto update)
+    {
+        _logger.LogInformation(
+            "Broadcasting status update for agent {AgentId}: {Status}",
+            update.AgentId, update.Status);
+
+        await Clients.All.AgentStatusChanged(update);
+    }
+
+    /// <summary>
+    /// Adds the calling connection to the fleet group.
+    /// Once joined, the client will receive all agent status updates.
+    /// </summary>
+    public async Task JoinFleet()
+    {
+        await Groups.AddToGroupAsync(Context.ConnectionId, FleetGroupName);
+        _logger.LogDebug("Connection {ConnectionId} joined fleet group", Context.ConnectionId);
+    }
+
+    /// <summary>
+    /// Removes the calling connection from the fleet group.
+    /// </summary>
+    public async Task LeaveFleet()
+    {
+        await Groups.RemoveFromGroupAsync(Context.ConnectionId, FleetGroupName);
+        _logger.LogDebug("Connection {ConnectionId} left fleet group", Context.ConnectionId);
+    }
+
+    /// <summary>
+    /// Overrides <see cref="Hub{T}.OnDisconnectedAsync"/> to log disconnections.
+    /// SignalR automatically removes disconnected connections from all groups.
+    /// </summary>
+    /// <param name="exception">Exception that caused the disconnection, if any.</param>
+    public override Task OnDisconnectedAsync(Exception? exception)
+    {
+        _logger.LogDebug("Connection {ConnectionId} disconnected", Context.ConnectionId);
+        return base.OnDisconnectedAsync(exception);
+    }
+
+    /// <summary>
+    /// The SignalR group name for the entire fleet (all agents).
+    /// </summary>
+    internal const string FleetGroupName = "fleet";
+}
+
+/// <summary>
+/// Strongly-typed client interface for the AgentStatus SignalR hub.
+/// Defines the methods the server can invoke on connected clients
+/// to push real-time agent status updates.
+/// </summary>
+public interface IAgentStatusClient
+{
+    /// <summary>
+    /// Pushes an agent status change to all subscribed clients.
+    /// Fired whenever an agent's operational status changes
+    /// (e.g., idle → active, active → thinking, active → error).
+    /// </summary>
+    /// <param name="update">The full status update payload.</param>
+    /// <returns>A Task that completes when the client has processed the update.</returns>
+    Task AgentStatusChanged(AgentStatusUpdateDto update);
+}
+
+/// <summary>
+/// Extension methods for pushing real-time agent updates through
+/// the <see cref="IHubContext{T}"/> of <see cref="AgentStatusHub"/>.
+///
+/// <para>
+/// These methods are intended to be called from background services
+/// or other server-side code that detects an agent state change,
+/// using the injected <c>IHubContext&lt;AgentStatusHub, IAgentStatusClient&gt;</c>.
+/// </para>
+/// </summary>
+public static class AgentStatusHubExtensions
+{
+    /// <summary>
+    /// Pushes an agent status update to all connected clients.
+    ///
+    /// <para>
+    /// Call this from any background service when an agent's
+    /// operational status changes (e.g., the Gateway reports a
+    /// session transition from "running" to "done").
+    /// </para>
+    /// </summary>
+    /// <param name="hubContext">The hub context injected via DI.</param>
+    /// <param name="update">The agent status update payload.</param>
+    /// <returns>A Task that completes when the message has been sent to all clients.</returns>
+    public static async Task PushStatusUpdateAsync(
+        this IHubContext<AgentStatusHub, IAgentStatusClient> hubContext,
+        AgentStatusUpdateDto update)
+    {
+        await hubContext.Clients.All.AgentStatusChanged(update);
+    }
+
+    /// <summary>
+    /// Pushes an agent status update to clients subscribed to the fleet group.
+    /// </summary>
+    /// <param name="hubContext">The hub context injected via DI.</param>
+    /// <param name="update">The agent status update payload.</param>
+    /// <returns>A Task that completes when the message has been sent to the fleet group.</returns>
+    public static async Task PushStatusUpdateToFleetAsync(
+        this IHubContext<AgentStatusHub, IAgentStatusClient> hubContext,
+        AgentStatusUpdateDto update)
+    {
+        await hubContext.Clients.Group(AgentStatusHub.FleetGroupName)
+            .AgentStatusChanged(update);
+    }
+}

backend/Migrations/20260426101703_CreateAgentsTable.Designer.cs

@@ -0,0 +1,94 @@
+// <auto-generated />
+using System;
+using ControlCenter.Api.Data;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+using Npgsql.EntityFrameworkCore.PostgreSQL.Metadata;
+
+#nullable disable
+
+namespace ControlCenter.Api.Migrations
+{
+    [DbContext(typeof(AppDbContext))]
+    [Migration("20260426101703_CreateAgentsTable")]
+    partial class CreateAgentsTable
+    {
+        /// <inheritdoc />
+        protected override void BuildTargetModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder
+                .HasAnnotation("ProductVersion", "9.0.4")
+                .HasAnnotation("Relational:MaxIdentifierLength", 63);
+
+            NpgsqlModelBuilderExtensions.HasPostgresEnum(modelBuilder, "agent_status", new[] { "active", "idle", "thinking", "error" });
+            NpgsqlModelBuilderExtensions.UseIdentityByDefaultColumns(modelBuilder);
+
+            modelBuilder.Entity("ControlCenter.Api.Entities.Agent", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("uuid")
+                        .HasColumnName("id");
+
+                    b.Property<string>("Channel")
+                        .IsRequired()
+                        .HasColumnType("text")
+                        .HasColumnName("channel");
+
+                    b.Property<DateTime>("CreatedAt")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("timestamptz")
+                        .HasColumnName("created_at")
+                        .HasDefaultValueSql("now()");
+
+                    b.Property<DateTime>("LastActivity")
+                        .HasColumnType("timestamptz")
+                        .HasColumnName("last_activity");
+
+                    b.Property<int?>("Progress")
+                        .HasColumnType("integer")
+                        .HasColumnName("progress");
+
+                    b.Property<string>("SessionKey")
+                        .IsRequired()
+                        .HasColumnType("text")
+                        .HasColumnName("session_key");
+
+                    b.Property<int>("Status")
+                        .HasColumnType("agent_status")
+                        .HasColumnName("status");
+
+                    b.Property<string>("Task")
+                        .HasColumnType("text")
+                        .HasColumnName("task");
+
+                    b.Property<DateTime>("UpdatedAt")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("timestamptz")
+                        .HasColumnName("updated_at")
+                        .HasDefaultValueSql("now()");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("Channel")
+                        .HasDatabaseName("ix_agents_channel");
+
+                    b.HasIndex("SessionKey")
+                        .IsUnique()
+                        .HasDatabaseName("ix_agents_session_key");
+
+                    b.HasIndex("Status")
+                        .HasDatabaseName("ix_agents_status");
+
+                    b.ToTable("agents", null, t =>
+                        {
+                            t.HasCheckConstraint("ck_agents_progress_range", "progress IS NULL OR (progress >= 0 AND progress <= 100)");
+                        });
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}

backend/Migrations/20260426101703_CreateAgentsTable.cs

@@ -0,0 +1,61 @@
+using System;
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace ControlCenter.Api.Migrations
+{
+    /// <inheritdoc />
+    public partial class CreateAgentsTable : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AlterDatabase()
+                .Annotation("Npgsql:Enum:agent_status", "active,idle,thinking,error");
+
+            migrationBuilder.CreateTable(
+                name: "agents",
+                columns: table => new
+                {
+                    id = table.Column<Guid>(type: "uuid", nullable: false),
+                    status = table.Column<int>(type: "agent_status", nullable: false),
+                    task = table.Column<string>(type: "text", nullable: true),
+                    progress = table.Column<int>(type: "integer", nullable: true),
+                    session_key = table.Column<string>(type: "text", nullable: false),
+                    channel = table.Column<string>(type: "text", nullable: false),
+                    last_activity = table.Column<DateTime>(type: "timestamptz", nullable: false),
+                    created_at = table.Column<DateTime>(type: "timestamptz", nullable: false, defaultValueSql: "now()"),
+                    updated_at = table.Column<DateTime>(type: "timestamptz", nullable: false, defaultValueSql: "now()")
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_agents", x => x.id);
+                    table.CheckConstraint("ck_agents_progress_range", "progress IS NULL OR (progress >= 0 AND progress <= 100)");
+                });
+
+            migrationBuilder.CreateIndex(
+                name: "ix_agents_channel",
+                table: "agents",
+                column: "channel");
+
+            migrationBuilder.CreateIndex(
+                name: "ix_agents_session_key",
+                table: "agents",
+                column: "session_key",
+                unique: true);
+
+            migrationBuilder.CreateIndex(
+                name: "ix_agents_status",
+                table: "agents",
+                column: "status");
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropTable(
+                name: "agents");
+        }
+    }
+}

backend/Migrations/AppDbContextModelSnapshot.cs

@@ -0,0 +1,91 @@
+// <auto-generated />
+using System;
+using ControlCenter.Api.Data;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+using Npgsql.EntityFrameworkCore.PostgreSQL.Metadata;
+
+#nullable disable
+
+namespace ControlCenter.Api.Migrations
+{
+    [DbContext(typeof(AppDbContext))]
+    partial class AppDbContextModelSnapshot : ModelSnapshot
+    {
+        protected override void BuildModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder
+                .HasAnnotation("ProductVersion", "9.0.4")
+                .HasAnnotation("Relational:MaxIdentifierLength", 63);
+
+            NpgsqlModelBuilderExtensions.HasPostgresEnum(modelBuilder, "agent_status", new[] { "active", "idle", "thinking", "error" });
+            NpgsqlModelBuilderExtensions.UseIdentityByDefaultColumns(modelBuilder);
+
+            modelBuilder.Entity("ControlCenter.Api.Entities.Agent", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("uuid")
+                        .HasColumnName("id");
+
+                    b.Property<string>("Channel")
+                        .IsRequired()
+                        .HasColumnType("text")
+                        .HasColumnName("channel");
+
+                    b.Property<DateTime>("CreatedAt")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("timestamptz")
+                        .HasColumnName("created_at")
+                        .HasDefaultValueSql("now()");
+
+                    b.Property<DateTime>("LastActivity")
+                        .HasColumnType("timestamptz")
+                        .HasColumnName("last_activity");
+
+                    b.Property<int?>("Progress")
+                        .HasColumnType("integer")
+                        .HasColumnName("progress");
+
+                    b.Property<string>("SessionKey")
+                        .IsRequired()
+                        .HasColumnType("text")
+                        .HasColumnName("session_key");
+
+                    b.Property<int>("Status")
+                        .HasColumnType("agent_status")
+                        .HasColumnName("status");
+
+                    b.Property<string>("Task")
+                        .HasColumnType("text")
+                        .HasColumnName("task");
+
+                    b.Property<DateTime>("UpdatedAt")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("timestamptz")
+                        .HasColumnName("updated_at")
+                        .HasDefaultValueSql("now()");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("Channel")
+                        .HasDatabaseName("ix_agents_channel");
+
+                    b.HasIndex("SessionKey")
+                        .IsUnique()
+                        .HasDatabaseName("ix_agents_session_key");
+
+                    b.HasIndex("Status")
+                        .HasDatabaseName("ix_agents_status");
+
+                    b.ToTable("agents", null, t =>
+                        {
+                            t.HasCheckConstraint("ck_agents_progress_range", "progress IS NULL OR (progress >= 0 AND progress <= 100)");
+                        });
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}

backend/Program.cs

@@ -0,0 +1,38 @@
+using ControlCenter.Api.Data;
+using ControlCenter.Api.Hubs;
+using Microsoft.EntityFrameworkCore;
+
+var builder = WebApplication.CreateBuilder(args);
+
+// Add services to the container.
+builder.Services.AddOpenApi();
+
+// Register SignalR for real-time agent status updates
+builder.Services.AddSignalR();
+
+// Register DbContext with PostgreSQL
+builder.Services.AddDbContext<AppDbContext>(options =>
+{
+    var connectionString = builder.Configuration.GetConnectionString("DefaultConnection")
+        ?? "Host=localhost;Database=control_center;Username=postgres;Password=postgres";
+
+    options.UseNpgsql(connectionString, npgsqlOptions =>
+    {
+        npgsqlOptions.MigrationsAssembly(typeof(AppDbContext).Assembly.FullName);
+    });
+});
+
+var app = builder.Build();
+
+// Configure the HTTP request pipeline.
+if (app.Environment.IsDevelopment())
+{
+    app.MapOpenApi();
+}
+
+app.UseHttpsRedirection();
+
+// Map SignalR hubs
+app.MapHub<AgentStatusHub>("/hubs/agent-status");
+
+app.Run();

backend/Properties/launchSettings.json

@@ -0,0 +1,23 @@
+{
+  "$schema": "https://json.schemastore.org/launchsettings.json",
+  "profiles": {
+    "http": {
+      "commandName": "Project",
+      "dotnetRunMessages": true,
+      "launchBrowser": false,
+      "applicationUrl": "http://localhost:5178",
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      }
+    },
+    "https": {
+      "commandName": "Project",
+      "dotnetRunMessages": true,
+      "launchBrowser": false,
+      "applicationUrl": "https://localhost:7041;http://localhost:5178",
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      }
+    }
+  }
+}

backend/appsettings.Development.json

@@ -0,0 +1,8 @@
+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning"
+    }
+  }
+}

backend/appsettings.json

@@ -0,0 +1,12 @@
+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning"
+    }
+  },
+  "AllowedHosts": "*",
+  "ConnectionStrings": {
+    "DefaultConnection": "Host=localhost;Database=control_center;Username=postgres;Password=postgres"
+  }
+}