Any Custom Frontend with Gradio's Backend

A new feature, `gradio.Server`, allows developers to combine a custom frontend with Gradio's backend engine. This enables the use of any frontend framework, like React or plain HTML/JS, while still leveraging Gradio's queuing system, concurrency control, and ZeroGPU support on Hugging Face Spaces. An example application demonstrates how to build a rich UI with a custom frontend that communicates with a Python backend running an ML model via the `@app.api()` decorator. This approach effectively turns Gradio into a flexible backend framework, giving developers the choice to use Gradio's UI or their own.