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

server/wsgi.py

@@ -8,6 +8,7 @@ from server.routes.holidays import holidays_bp
 from server.routes.academic_periods import academic_periods_bp
 from server.routes.groups import groups_bp
 from server.routes.clients import clients_bp
+from server.routes.client_logs import client_logs_bp
 from server.routes.auth import auth_bp
 from server.routes.users import users_bp
 from server.routes.system_settings import system_settings_bp
@@ -46,6 +47,7 @@ else:
 app.register_blueprint(auth_bp)
 app.register_blueprint(users_bp)
 app.register_blueprint(clients_bp)
+app.register_blueprint(client_logs_bp)
 app.register_blueprint(groups_bp)
 app.register_blueprint(events_bp)
 app.register_blueprint(event_exceptions_bp)