feat(monitoring): add server-side client logging and health infrastructure

- add Alembic migration c1d2e3f4g5h6 for client monitoring:
  - create client_logs table with FK to clients.uuid and performance indexes
  - extend clients with process/health tracking fields
- extend data model with ClientLog, LogLevel, ProcessStatus, and ScreenHealthStatus
- enhance listener MQTT handling:
  - subscribe to logs and health topics
  - persist client logs from infoscreen/{uuid}/logs/{level}
  - process health payloads and enrich heartbeat-derived client state
- add monitoring API blueprint server/routes/client_logs.py:
  - GET /api/client-logs/<uuid>/logs
  - GET /api/client-logs/summary
  - GET /api/client-logs/recent-errors
  - GET /api/client-logs/test
- register client_logs blueprint in server/wsgi.py
- align compose/dev runtime for listener live-code execution
- add client-side implementation docs:
  - CLIENT_MONITORING_SPECIFICATION.md
  - CLIENT_MONITORING_IMPLEMENTATION_GUIDE.md
- update TECH-CHANGELOG.md and copilot-instructions.md:
  - document monitoring changes
  - codify post-release technical-notes/no-version-bump convention

docker-compose.yml

@@ -18,6 +18,7 @@ services:
     environment:
       - DB_CONN=mysql+pymysql://${DB_USER}:${DB_PASSWORD}@db/${DB_NAME}
       - DB_URL=mysql+pymysql://${DB_USER}:${DB_PASSWORD}@db/${DB_NAME}
+      - API_BASE_URL=http://server:8000
         - ENV=${ENV:-development}
         - FLASK_SECRET_KEY=${FLASK_SECRET_KEY:-dev-secret-key-change-in-production}
       - DEFAULT_SUPERADMIN_USERNAME=${DEFAULT_SUPERADMIN_USERNAME:-superadmin}