feat: Add Chat UX improvements with notifications and @mention support

- Add ActionBar component with expandable toolbar for mobile
- Add @mention functionality with autocomplete dropdown
- Add browser notification system (push, sound, vibration)
- Add NotificationSettings modal for user preferences
- Add mention badges on room list cards
- Add ReportPreview with Markdown rendering and copy/download
- Add message copy functionality with hover actions
- Add backend mentions field to messages with Alembic migration
- Add lots field to rooms, remove templates
- Optimize WebSocket database session handling
- Various UX polish (animations, accessibility)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

app/main.py

@@ -13,10 +13,10 @@ from app.modules.auth import router as auth_router
 from app.modules.auth.users_router import router as users_router
 from app.modules.auth.middleware import auth_middleware
 from app.modules.chat_room import router as chat_room_router
-from app.modules.chat_room.services.template_service import template_service
 from app.modules.realtime import router as realtime_router
 from app.modules.file_storage import router as file_storage_router
 from app.modules.report_generation import router as report_generation_router
+from app.modules.report_generation import health_router as report_health_router
 
 # Frontend build directory
 FRONTEND_DIR = Path(__file__).parent.parent / "frontend" / "dist"
@@ -53,24 +53,17 @@ app.include_router(chat_room_router)
 app.include_router(realtime_router)
 app.include_router(file_storage_router)
 app.include_router(report_generation_router)
+app.include_router(report_health_router)
 
 
 @app.on_event("startup")
 async def startup_event():
     """Initialize application on startup"""
-    from app.core.database import SessionLocal
     from app.core.minio_client import initialize_bucket
     import logging
 
     logger = logging.getLogger(__name__)
 
-    # Initialize default templates
-    db = SessionLocal()
-    try:
-        template_service.initialize_default_templates(db)
-    finally:
-        db.close()
-
     # Initialize MinIO bucket
     try:
         if initialize_bucket():
@@ -80,6 +73,10 @@ async def startup_event():
     except Exception as e:
         logger.warning(f"MinIO connection failed: {e} - file uploads will be unavailable")
 
+    # Check DIFY API Key configuration
+    if not settings.DIFY_API_KEY:
+        logger.warning("DIFY_API_KEY not configured - AI report generation will be unavailable")
+
 
 @app.get("/api/health")
 async def health_check():