docs: update DEVELOPMENT_LOG for v0.0.4 collector work

DEVELOPMENT_LOG.md

@@ -14,6 +14,36 @@
 
 ## Completed Work
 
+### v0.0.4 — Gateway Data Collection Service
+**Status:** ✅ COMPLETED  
+**Date:** 2026-05-11  
+**Agent:** Neo (build) + Ripley (fix/verify/commit)
+
+**Files Created:**
+- `src/backend/app/services/monitoring/__init__.py` — Package init, exports GatewayCollectorService
+- `src/backend/app/services/monitoring/gateway_collector.py` — Background asyncio collector (544→510 lines after fixes)
+- `src/backend/app/services/monitoring/models.py` — Pydantic schemas for RPC response parsing
+
+**Files Modified:**
+- `src/backend/app/main.py` — Added asyncio import, collector startup/shutdown in lifespan
+- `src/backend/app/models/monitoring.py` — Fixed FK definitions (Column(UUID, ForeignKey) → Field(foreign_key=))
+- `src/backend/app/models/alert_rules.py` — Fixed FK definitions, added missing gateway_id field
+
+**Bugs Fixed by Ripley:**
+- Duplicate `select` imports (sqlalchemy + sqlmodel)
+- Removed OpenClawDBService inheritance (collector uses session factory pattern)
+- Removed unused imports (datetime, timezone, UUID, TYPE_CHECKING)
+- Fixed `Column(UUID, ForeignKey(...))` — Python uuid.UUID is not a SQLAlchemy type
+- Added missing `gateway_id` field to AlertRule model
+- Cleaned up runtime imports in lifespan (moved to module-level)
+
+**Verification:**
+- Docker build passes
+- Backend starts successfully (logs `app.lifecycle.gateway_collector.no_gateways`)
+- Collector class imports correctly in container
+
+---
+
 ### v0.0.2 — Base Platform Setup
 **Status:** ✅ COMPLETED  
 **Date:** 2026-05-10