Fix app.py: Use exec() to properly execute gradio_app as __main__

The import approach didn't work because gradio_app's
if __name__ == '__main__' block wouldn't execute when imported.
Using exec() ensures the code runs with __name__ set to '__main__'.

app.py

@@ -18,7 +18,9 @@ sys.argv = [
     '--port', '7860'
 ]
 
-# Import gradio_app to execute its if __name__ == '__main__' block
-# This is safe because we've already set sys.argv before import
+# Execute gradio_app.py as __main__ module
+# We use exec() to run the code with __name__ == '__main__'
 if __name__ == '__main__':
-    import gradio_app
+    with open('gradio_app.py', 'r') as f:
+        code = f.read()
+    exec(code, {'__name__': '__main__', '__file__': 'gradio_app.py'})