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>

docs/reports/qa-automation/escalated/home-localadmin-src-mosaic-stack-apps-api-src-federation-identity-linking.service.spec.ts_20260203-1248_5_remediation_needed.md

@@ -0,0 +1,17 @@
+# QA Remediation Report
+
+**File:** /home/localadmin/src/mosaic-stack/apps/api/src/federation/identity-linking.service.spec.ts
+**Tool Used:** Edit
+**Epic:** general
+**Iteration:** 5
+**Generated:** 2026-02-03 12:48:45
+
+## Status
+Pending QA validation
+
+## Next Steps
+This report was created by the QA automation hook.
+To process this report, run:
+```bash
+claude -p "Use Task tool to launch universal-qa-agent for report: /home/localadmin/src/mosaic-stack/docs/reports/qa-automation/escalated/home-localadmin-src-mosaic-stack-apps-api-src-federation-identity-linking.service.spec.ts_20260203-1248_5_remediation_needed.md"
+```

docs/reports/qa-automation/escalated/home-localadmin-src-mosaic-stack-apps-api-src-federation-identity-linking.service.ts_20260203-1252_5_remediation_needed.md

@@ -0,0 +1,17 @@
+# QA Remediation Report
+
+**File:** /home/localadmin/src/mosaic-stack/apps/api/src/federation/identity-linking.service.ts
+**Tool Used:** Edit
+**Epic:** general
+**Iteration:** 5
+**Generated:** 2026-02-03 12:52:56
+
+## Status
+Pending QA validation
+
+## Next Steps
+This report was created by the QA automation hook.
+To process this report, run:
+```bash
+claude -p "Use Task tool to launch universal-qa-agent for report: /home/localadmin/src/mosaic-stack/docs/reports/qa-automation/escalated/home-localadmin-src-mosaic-stack-apps-api-src-federation-identity-linking.service.ts_20260203-1252_5_remediation_needed.md"
+```