feat(#93): implement agent spawn via federation

Implements FED-010: Agent Spawn via Federation feature that enables
spawning and managing Claude agents on remote federated Mosaic Stack
instances via COMMAND message type.

Features:
- Federation agent command types (spawn, status, kill)
- FederationAgentService for handling agent operations
- Integration with orchestrator's agent spawner/lifecycle services
- API endpoints for spawning, querying status, and killing agents
- Full command routing through federation COMMAND infrastructure
- Comprehensive test coverage (12/12 tests passing)

Architecture:
- Hub → Spoke: Spawn agents on remote instances
- Command flow: FederationController → FederationAgentService →
  CommandService → Remote Orchestrator
- Response handling: Remote orchestrator returns agent status/results
- Security: Connection validation, signature verification

Files created:
- apps/api/src/federation/types/federation-agent.types.ts
- apps/api/src/federation/federation-agent.service.ts
- apps/api/src/federation/federation-agent.service.spec.ts

Files modified:
- apps/api/src/federation/command.service.ts (agent command routing)
- apps/api/src/federation/federation.controller.ts (agent endpoints)
- apps/api/src/federation/federation.module.ts (service registration)
- apps/orchestrator/src/api/agents/agents.controller.ts (status endpoint)
- apps/orchestrator/src/api/agents/agents.module.ts (lifecycle integration)

Testing:
- 12/12 tests passing for FederationAgentService
- All command service tests passing
- TypeScript compilation successful
- Linting passed

Refs #93

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

apps/api/src/tasks/dto/query-tasks.dto.spec.ts

@@ -24,7 +24,7 @@ describe("QueryTasksDto", () => {
 
     const errors = await validate(dto);
     expect(errors.length).toBeGreaterThan(0);
-    expect(errors.some(e => e.property === "workspaceId")).toBe(true);
+    expect(errors.some((e) => e.property === "workspaceId")).toBe(true);
   });
 
   it("should accept valid status filter", async () => {

apps/api/src/tasks/tasks.controller.spec.ts

@@ -106,18 +106,10 @@ describe("TasksController", () => {
 
       mockTasksService.create.mockResolvedValue(mockTask);
 
-      const result = await controller.create(
-        createDto,
-        mockWorkspaceId,
-        mockRequest.user
-      );
+      const result = await controller.create(createDto, mockWorkspaceId, mockRequest.user);
 
       expect(result).toEqual(mockTask);
-      expect(service.create).toHaveBeenCalledWith(
-        mockWorkspaceId,
-        mockUserId,
-        createDto
-      );
+      expect(service.create).toHaveBeenCalledWith(mockWorkspaceId, mockUserId, createDto);
     });
   });
 
@@ -247,11 +239,7 @@ describe("TasksController", () => {
 
       await controller.remove(mockTaskId, mockWorkspaceId, mockRequest.user);
 
-      expect(service.remove).toHaveBeenCalledWith(
-        mockTaskId,
-        mockWorkspaceId,
-        mockUserId
-      );
+      expect(service.remove).toHaveBeenCalledWith(mockTaskId, mockWorkspaceId, mockUserId);
     });
 
     it("should throw error if workspaceId not found", async () => {
@@ -262,11 +250,7 @@ describe("TasksController", () => {
 
       await controller.remove(mockTaskId, mockWorkspaceId, mockRequest.user);
 
-      expect(service.remove).toHaveBeenCalledWith(
-        mockTaskId,
-        mockWorkspaceId,
-        mockUserId
-      );
+      expect(service.remove).toHaveBeenCalledWith(mockTaskId, mockWorkspaceId, mockUserId);
     });
   });
 });