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.spec.ts

@@ -13,6 +13,8 @@ describe("AgentsController", () => {
   };
   let spawnerService: {
     spawnAgent: ReturnType<typeof vi.fn>;
+    listAgentSessions: ReturnType<typeof vi.fn>;
+    getAgentSession: ReturnType<typeof vi.fn>;
   };
   let lifecycleService: {
     getAgentLifecycleState: ReturnType<typeof vi.fn>;
@@ -30,6 +32,8 @@ describe("AgentsController", () => {
 
     spawnerService = {
       spawnAgent: vi.fn(),
+      listAgentSessions: vi.fn(),
+      getAgentSession: vi.fn(),
     };
 
     lifecycleService = {
@@ -58,6 +62,109 @@ describe("AgentsController", () => {
     expect(controller).toBeDefined();
   });
 
+  describe("listAgents", () => {
+    it("should return empty array when no agents exist", () => {
+      // Arrange
+      spawnerService.listAgentSessions.mockReturnValue([]);
+
+      // Act
+      const result = controller.listAgents();
+
+      // Assert
+      expect(spawnerService.listAgentSessions).toHaveBeenCalled();
+      expect(result).toEqual([]);
+    });
+
+    it("should return all agent sessions with mapped status", () => {
+      // Arrange
+      const sessions = [
+        {
+          agentId: "agent-1",
+          taskId: "task-1",
+          agentType: "worker" as const,
+          state: "running" as const,
+          context: {
+            repository: "repo",
+            branch: "main",
+            workItems: [],
+          },
+          spawnedAt: new Date("2026-02-05T12:00:00Z"),
+        },
+        {
+          agentId: "agent-2",
+          taskId: "task-2",
+          agentType: "reviewer" as const,
+          state: "completed" as const,
+          context: {
+            repository: "repo",
+            branch: "main",
+            workItems: [],
+          },
+          spawnedAt: new Date("2026-02-05T11:00:00Z"),
+          completedAt: new Date("2026-02-05T11:30:00Z"),
+        },
+        {
+          agentId: "agent-3",
+          taskId: "task-3",
+          agentType: "tester" as const,
+          state: "failed" as const,
+          context: {
+            repository: "repo",
+            branch: "main",
+            workItems: [],
+          },
+          spawnedAt: new Date("2026-02-05T10:00:00Z"),
+          error: "Test execution failed",
+        },
+      ];
+      spawnerService.listAgentSessions.mockReturnValue(sessions);
+
+      // Act
+      const result = controller.listAgents();
+
+      // Assert
+      expect(spawnerService.listAgentSessions).toHaveBeenCalled();
+      expect(result).toHaveLength(3);
+      expect(result[0]).toEqual({
+        agentId: "agent-1",
+        taskId: "task-1",
+        status: "running",
+        agentType: "worker",
+        spawnedAt: "2026-02-05T12:00:00.000Z",
+        completedAt: undefined,
+        error: undefined,
+      });
+      expect(result[1]).toEqual({
+        agentId: "agent-2",
+        taskId: "task-2",
+        status: "completed",
+        agentType: "reviewer",
+        spawnedAt: "2026-02-05T11:00:00.000Z",
+        completedAt: "2026-02-05T11:30:00.000Z",
+        error: undefined,
+      });
+      expect(result[2]).toEqual({
+        agentId: "agent-3",
+        taskId: "task-3",
+        status: "failed",
+        agentType: "tester",
+        spawnedAt: "2026-02-05T10:00:00.000Z",
+        completedAt: undefined,
+        error: "Test execution failed",
+      });
+    });
+
+    it("should handle errors gracefully", () => {
+      // Arrange
+      spawnerService.listAgentSessions.mockImplementation(() => {
+        throw new Error("Service unavailable");
+      });
+
+      // Act & Assert
+      expect(() => controller.listAgents()).toThrow("Failed to list agents: Service unavailable");
+    });
+  });
+
   describe("spawn", () => {
     const validRequest = {
       taskId: "task-123",