feat(CUB-19): implement AgentStatus SignalR hub for real-time updates

- Add AgentStatusHub with typed IAgentStatusClient interface
  - Hub at /hubs/agent-status (matches design spec)
  - Fleet group + per-agent group subscription
  - AgentStatusChanged and AgentTaskProgress push events
  - Extension methods for server-side push via IHubContext

- Add GatewayEventBridgeService background service
  - Connects to OpenClaw Gateway WebSocket (v3 protocol)
  - Handles challenge → connect → hello-ok handshake
  - Bridges sessions.changed, session.message, session.tool events
  - Translates Gateway session status to AgentStatus enum
  - Maintains in-memory fleet state for snapshot queries

- Add REST API controllers
  - GET /api/agents — fleet status snapshot
  - GET /api/agents/{agentId} — single agent status
  - GET /api/logs/{agentId} — agent session logs (stub)
  - POST /api/command/stop/{agentId} — stop agent
  - POST /api/command/restart/{agentId} — restart agent
  - POST /api/command/steer/{agentId} — inject message

- Add models matching TypeScript spec interfaces
  - AgentStatusUpdate, TaskProgressUpdate, AgentCardData
  - AgentStatus enum (active/idle/thinking/error)

- Configure CORS with credentials for SignalR WebSocket
- Configure Swagger/OpenAPI with XML doc comments
- Agent role map matching frontend AGENT_ROLES constant

backend/ControlCenter/Controllers/LogsController.cs

@@ -0,0 +1,87 @@
+using Microsoft.AspNetCore.Mvc;
+
+namespace ControlCenter.Controllers;
+
+/// <summary>
+/// REST API for querying agent session logs.
+/// Provides historical message and tool call logs for a specific agent.
+///
+/// <para>API contract for Rex (Frontend):</para>
+/// <list type="bullet">
+///   <item><c>GET /api/logs/{agentId}</c> — Returns recent logs for an agent</item>
+///   <item><c>GET /api/logs/{agentId}/tools</c> — Returns recent tool calls for an agent</item>
+/// </list>
+///
+/// <para>Log data is sourced from the OpenClaw Gateway's transcript files.
+/// The Gateway's <c>logs.tail</c> RPC provides the raw data, and this
+/// controller formats it for the frontend.</para>
+/// </summary>
+[ApiController]
+[Route("api/[controller]")]
+public class LogsController : ControllerBase
+{
+    private readonly ILogger<LogsController> _logger;
+
+    public LogsController(ILogger<LogsController> logger)
+    {
+        _logger = logger;
+    }
+
+    /// <summary>
+    /// Gets recent session logs for a specific agent.
+    /// Returns the last N messages from the agent's active session transcript.
+    /// </summary>
+    /// <param name="agentId">The agent identifier, e.g. "otto", "dex".</param>
+    /// <param name="limit">Maximum number of log entries to return (default: 50, max: 200).</param>
+    /// <returns>An array of log entries for the agent.</returns>
+    /// <response code="200">Returns the agent's recent logs.</response>
+    /// <response code="404">No active session found for the agent.</response>
+    [HttpGet("{agentId}")]
+    [ProducesResponseType(StatusCodes.Status200OK)]
+    [ProducesResponseType(StatusCodes.Status404NotFound)]
+    public IActionResult GetLogs(string agentId, [FromQuery] int limit = 50)
+    {
+        limit = Math.Clamp(limit, 1, 200);
+
+        _logger.LogDebug("Logs requested for agent {AgentId}, limit {Limit}", agentId, limit);
+
+        // TODO: Implement log retrieval by calling the Gateway's logs.tail RPC
+        // or reading transcript files. For now, return an empty array as the
+        // bridge service will provide this data when fully integrated.
+        return Ok(new
+        {
+            agentId,
+            logs = Array.Empty<object>(),
+            count = 0,
+            hasMore = false
+        });
+    }
+
+    /// <summary>
+    /// Gets recent tool call logs for a specific agent.
+    /// Returns the last N tool invocations from the agent's session.
+    /// </summary>
+    /// <param name="agentId">The agent identifier.</param>
+    /// <param name="limit">Maximum number of tool entries to return (default: 20, max: 100).</param>
+    /// <returns>An array of tool call entries for the agent.</returns>
+    /// <response code="200">Returns the agent's recent tool calls.</response>
+    /// <response code="404">No active session found for the agent.</response>
+    [HttpGet("{agentId}/tools")]
+    [ProducesResponseType(StatusCodes.Status200OK)]
+    [ProducesResponseType(StatusCodes.Status404NotFound)]
+    public IActionResult GetToolLogs(string agentId, [FromQuery] int limit = 20)
+    {
+        limit = Math.Clamp(limit, 1, 100);
+
+        _logger.LogDebug("Tool logs requested for agent {AgentId}, limit {Limit}", agentId, limit);
+
+        // TODO: Implement tool log retrieval. Return empty for now.
+        return Ok(new
+        {
+            agentId,
+            tools = Array.Empty<object>(),
+            count = 0,
+            hasMore = false
+        });
+    }
+}