Add Phase 10-12 implementation: multi-tenant, marketplace, observability

Major additions:
- marketplace/: Agent template registry with FTS5 search, ratings, versioning
- observability/: Prometheus metrics, distributed tracing, structured logging
- ledger/migrations/: Database migration scripts for multi-tenant support
- tests/governance/: 15 new test files for phases 6-12 (295 total tests)
- bin/validate-phases: Full 12-phase validation script

New features:
- Multi-tenant support with tenant isolation and quota enforcement
- Agent marketplace with semantic versioning and search
- Observability with metrics, tracing, and log correlation
- Tier-1 agent bootstrap scripts

Updated components:
- ledger/api.py: Extended API for tenants, marketplace, observability
- ledger/schema.sql: Added tenant, project, marketplace tables
- testing/framework.ts: Enhanced test framework
- checkpoint/checkpoint.py: Improved checkpoint management

Archived:
- External integrations (Slack/GitHub/PagerDuty) moved to .archive/
- Old checkpoint files cleaned up

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

observability/STATUS.md

@@ -0,0 +1,82 @@
+# Status: Observability
+
+## Current Phase
+
+**COMPLETE**
+
+## Tasks
+
+| Status | Task | Updated |
+|--------|------|---------|
+| ✅ | Prometheus metrics module (Counter, Gauge, Histogram) | 2026-01-24 |
+| ✅ | Distributed tracing with span hierarchy | 2026-01-24 |
+| ✅ | Structured JSON logging with trace correlation | 2026-01-24 |
+| ✅ | SQLite persistence for logs and traces | 2026-01-24 |
+| ✅ | FastAPI routers for metrics, tracing, logging | 2026-01-24 |
+| ✅ | HTTP header context propagation (X-Trace-ID, X-Span-ID) | 2026-01-24 |
+| ✅ | Multi-tenant support | 2026-01-24 |
+| ✅ | MetricsMiddleware for automatic request tracking | 2026-01-24 |
+| ✅ | Module exports and unified API | 2026-01-24 |
+
+## Metrics Implemented
+
+- `agent_executions_total` - Counter by tier, action, status
+- `agent_execution_duration_seconds` - Histogram
+- `agent_violations_total` - Counter by type, severity
+- `agent_promotions_total` - Counter by tier transition
+- `api_requests_total` - Counter by method, endpoint, status
+- `api_request_duration_seconds` - Histogram
+- `component_health` - Gauge (Vault, DragonflyDB, Ledger)
+- `tenant_quota_usage_ratio` - Gauge
+- `governance_uptime_seconds` - Gauge
+- `marketplace_template_downloads_total` - Counter
+- `orchestration_requests_total` - Counter by model, status
+- `orchestration_tokens_total` - Counter by model
+
+## Dependencies
+
+| Dependency | Status | Purpose |
+|------------|--------|---------|
+| SQLite (ledger) | ✅ Available | Log/trace storage |
+| Vault | ✅ Available | Health check target |
+| DragonflyDB | ✅ Available | Health check target |
+
+## API Endpoints
+
+| Endpoint | Method | Status |
+|----------|--------|--------|
+| `/metrics` | GET | ✅ Prometheus format |
+| `/traces` | GET | ✅ List with filters |
+| `/traces/{trace_id}` | GET | ✅ Full details |
+| `/logs` | GET | ✅ Search with filters |
+| `/logs/trace/{trace_id}` | GET | ✅ Logs for trace |
+| `/logs/stats` | GET | ✅ Statistics |
+| `/logs/cleanup` | POST | ✅ Retention cleanup |
+| `/health/detailed` | GET | ✅ Component health |
+
+## Issues / Blockers
+
+*No current issues or blockers.*
+
+## Future Enhancements
+
+- Grafana dashboard templates
+- Jaeger/Zipkin export integration
+- Alert rule engine
+- SLO/SLI tracking
+- Trace sampling strategies
+
+## Activity Log
+
+### 2026-01-24 UTC
+- **Phase**: COMPLETE
+- **Action**: Documentation added
+- **Details**: Created README.md and STATUS.md for observability module
+
+### 2026-01-24 12:36 UTC
+- **Phase**: COMPLETE
+- **Action**: Module implementation complete
+- **Details**: metrics.py, tracing.py, logging.py implemented with full functionality
+
+---
+*Last updated: 2026-01-24 UTC*