Fixed entire calendar layout + chat layout + chat history

backend/core/database.py

@@ -17,6 +17,10 @@ def get_engine():
             raise ValueError("DB_URL is not set in Settings.")
         print(f"Connecting to database at {settings.DB_URL}")
         _engine = create_engine(settings.DB_URL)
+        try:
+            _engine.connect()
+        except Exception as e:
+            raise Exception("Database connection failed. Is the database server running?")
         Base.metadata.create_all(_engine)  # Create tables here
     return _engine