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>

testing/oversight/error_injector.py

@@ -228,9 +228,22 @@ class ErrorInjector:
 
         elif scope == InjectionScope.DATABASE and self._redis:
             if ":" in target:
-                # Redis key
-                backup["redis_value"] = self._redis.get(target)
-                backup["redis_type"] = self._redis.type(target)
+                # Redis key - handle different types
+                key_type = self._redis.type(target)
+                backup["redis_type"] = key_type
+                try:
+                    if key_type == "string":
+                        backup["redis_value"] = self._redis.get(target)
+                    elif key_type == "hash":
+                        backup["redis_value"] = self._redis.hgetall(target)
+                    elif key_type == "list":
+                        backup["redis_value"] = self._redis.lrange(target, 0, -1)
+                    elif key_type == "set":
+                        backup["redis_value"] = list(self._redis.smembers(target))
+                    else:
+                        backup["redis_value"] = None
+                except Exception:
+                    backup["redis_value"] = None
 
         return backup