fix(health): suppress 404 when health monitor disabled + fix audit test assertion

- Sidebar.svelte: defer healthStore.refresh() until feature flags confirm
  health_monitor is enabled; skip entirely when disabled
- health.js: remove throw error from catch block — log and return null
  instead, preventing 'Uncaught (in promise)' on expected 404
- test_report_audit_immutability.py: fix mock assertions —
  audit_service uses logger.reason/reflect/explore, not logger.info
- HealthStore and Sidebar now produce zero network noise when
  FEATURES__HEALTH_MONITOR=false

backend/src/models/translate.py

@@ -1,7 +1,7 @@
 # #region TranslateModels [C:3] [TYPE Module] [SEMANTICS sqlalchemy, translate, model, schema, dashboard, llm]
 # @BRIEF SQLAlchemy ORM models for LLM-based SQL/dashboard translation across dialects.
 # @LAYER: Domain
-# @RELATION INHERITS_FROM -> MappingModels:Base
+# @RELATION INHERITS -> [MappingModels]
 
 import uuid
 from datetime import UTC, datetime