updated server/app.py as per submit validation

server/app.py

@@ -12,4 +12,7 @@ import uvicorn
 app = create_fastapi_app(JewelryShopEnvironment, JewelryAction, JewelryObservation)
 
 def main():
-    uvicorn.run(app, host="0.0.0.0", port=8000)
+    uvicorn.run(app, host="0.0.0.0", port=8000)
+
+if __name__ == "__main__":
+    main()