caec3293ab
- Add system package with health check and version endpoints - Implement GET /api/system/health (public, no auth required) - Implement GET /api/system/version (public, no auth required) - Health endpoint returns version compatibility and migration status - Version endpoint returns detailed backend and database version info - Add comprehensive test suite (6 tests, all passing) - Register public routes in cmd/main.go - Fix maintenance handler to use pointers for migration structs Health endpoint response includes: - Backend version and required DB version - Current DB version and compatibility status - Pending migrations count - Timestamp Ready for Phase 5: Frontend Warning Banner integration