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/README.md

@@ -5,9 +5,11 @@ Clawdbot skills for integrating with Mosaic Stack APIs.
 ## Available Skills
 
 ### Brain (`brain/`)
+
 Quick capture and semantic search for ideas and brain dumps.
 
 **Features:**
+
 - Rapid brain dump capture
 - Semantic search across ideas
 - Tag management
@@ -16,9 +18,11 @@ Quick capture and semantic search for ideas and brain dumps.
 **Usage:** See `brain/SKILL.md` for documentation.
 
 ### Calendar (`calendar/`)
+
 Integration with Mosaic Stack's Events API for calendar management.
 
 **Features:**
+
 - Create events with rich metadata
 - Query events with flexible filtering
 - Update and reschedule events
@@ -27,9 +31,11 @@ Integration with Mosaic Stack's Events API for calendar management.
 **Usage:** See `calendar/SKILL.md` for documentation.
 
 ### Tasks (`tasks/`)
+
 Task management integration with Mosaic Stack's Tasks API.
 
 **Features:**
+
 - Create and manage tasks
 - Filter by status, priority, project
 - Track overdue tasks
@@ -38,9 +44,11 @@ Task management integration with Mosaic Stack's Tasks API.
 **Usage:** See `tasks/SKILL.md` for documentation.
 
 ### Gantt (`gantt/`)
+
 Query and analyze project timelines from Mosaic Stack's Projects API.
 
 **Features:**
+
 - Query project timelines and task lists
 - Check task dependencies and blocking relationships
 - Identify critical path items