Fixed Vercel build config for Streamlit deployment

vercel.json

@@ -3,11 +3,18 @@
   "builds": [
     {
       "src": "app.py",
-      "use": "@vercel/static-build",
-      "config": { "distDir": "public" }
+      "use": "@vercel/python"
     }
   ],
   "routes": [
-    { "src": "/(.*)", "dest": "/app.py" }
-  ]
-}
+    {
+      "src": "/(.*)",
+      "dest": "app.py"
+    }
+  ],
+  "env": {
+    "STREAMLIT_SERVER_HEADLESS": "true",
+    "STREAMLIT_SERVER_ENABLECORS": "false",
+    "STREAMLIT_SERVER_PORT": "8000"
+  }
+}