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>

packages/skills/calendar/SKILL.md

@@ -23,6 +23,7 @@ node scripts/calendar.js create \
 ```
 
 Natural language examples:
+
 - "Schedule a meeting tomorrow at 3pm"
 - "Create an event called 'dentist appointment' on Friday at 2pm"
 - "Add a recurring standup every weekday at 9am"
@@ -43,6 +44,7 @@ node scripts/calendar.js list --project-id "uuid-here"
 ```
 
 Natural language examples:
+
 - "What's on my calendar this week?"
 - "Show me upcoming events"
 - "What do I have scheduled for tomorrow?"
@@ -57,6 +59,7 @@ node scripts/calendar.js update EVENT_ID \
 ```
 
 Natural language examples:
+
 - "Move my 3pm meeting to 4pm"
 - "Reschedule tomorrow's dentist appointment to Friday"
 - "Change the location of my team meeting to Zoom"
@@ -68,6 +71,7 @@ node scripts/calendar.js delete EVENT_ID
 ```
 
 Natural language examples:
+
 - "Cancel my meeting with Sarah"
 - "Delete tomorrow's standup"
 - "Remove the 3pm appointment"
@@ -133,6 +137,7 @@ List queries return paginated results with metadata:
 ## Environment
 
 The script reads configuration from:
+
 - `MOSAIC_API_URL` (default: http://localhost:3001)
 - `MOSAIC_WORKSPACE_ID` (required)
 - `MOSAIC_API_TOKEN` (required for authentication)
@@ -142,6 +147,7 @@ Ensure these are set in the environment or `.env` file.
 ## Error Handling
 
 Common errors:
+
 - **401 Unauthorized**: Missing or invalid API token
 - **403 Forbidden**: Insufficient workspace permissions
 - **404 Not Found**: Event ID doesn't exist