Fix SyntaxError by moving global engine statement to function beginning

app/database.py

@@ -408,6 +408,8 @@ def get_current_database():
 
 # Create tables
 def create_tables():
+    global engine  # Declare global at the beginning
+    
     try:
         # Create all tables (only creates tables that don't exist)
         Base.metadata.create_all(bind=engine)
@@ -433,7 +435,6 @@ def create_tables():
             print(f"Created new database file: {db_path}")
             
             # Recreate engine with the new database
-            global engine
             engine.dispose()
             engine = create_engine(f"sqlite:///{db_path}", connect_args={"check_same_thread": False})