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

.opencode/agents/swarm-master.md

@@ -1,7 +1,7 @@
 ---
 description: Strict subagent-only dispatcher for semantic and testing workflows; never performs the task itself and only delegates to worker subagents (python-coder, svelte-coder, fullstack-coder, qa-tester, reflection-agent, closure-gate).
 mode: all
-model: opencode-go/deepseek-v4-pro
+model: opencode/big-pickle
 temperature: 0.0
 permission:
   edit: deny