feat(#233): Connect agent dashboard to real orchestrator API

- Add GET /agents endpoint to orchestrator controller
- Update AgentStatusWidget to fetch from real API instead of mock data
- Add comprehensive tests for listAgents endpoint
- Auto-refresh agent list every 30 seconds
- Display agent status with proper icons and formatting
- Show error states when API is unavailable

Fixes #233

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

apps/orchestrator/src/api/agents/agents.controller.ts

@@ -70,6 +70,47 @@ export class AgentsController {
     }
   }
 
+  /**
+   * List all agents
+   * @returns Array of all agent sessions with their status
+   */
+  @Get()
+  listAgents(): {
+    agentId: string;
+    taskId: string;
+    status: string;
+    agentType: string;
+    spawnedAt: string;
+    completedAt?: string;
+    error?: string;
+  }[] {
+    this.logger.log("Received request to list all agents");
+
+    try {
+      // Get all sessions from spawner service
+      const sessions = this.spawnerService.listAgentSessions();
+
+      // Map to response format
+      const agents = sessions.map((session) => ({
+        agentId: session.agentId,
+        taskId: session.taskId,
+        status: session.state,
+        agentType: session.agentType,
+        spawnedAt: session.spawnedAt.toISOString(),
+        completedAt: session.completedAt?.toISOString(),
+        error: session.error,
+      }));
+
+      this.logger.log(`Found ${agents.length.toString()} agents`);
+
+      return agents;
+    } catch (error: unknown) {
+      const errorMessage = error instanceof Error ? error.message : String(error);
+      this.logger.error(`Failed to list agents: ${errorMessage}`);
+      throw new Error(`Failed to list agents: ${errorMessage}`);
+    }
+  }
+
   /**
    * Get agent status
    * @param agentId Agent ID to query