Fix 20 pre-existing test failures:
- Update mock conversation DB schema with missing columns
- Add in-memory OPC database mock to avoid PostgreSQL dependency in CI
- Fix file download endpoint to check auth before revealing file existence
- Reload routers.system and routers.security in test_app for fresh config
- Reset cached Docker client in security router between tests
- Fix websocket auth test to properly check for connection rejection
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Gan, Jimmy
56a8ff28ad