Add a complete Next.js + Python full-stack example

[shloimy-wiesel]

The existing examples are great for demonstrating the Python SDK, but most focus on the backend in isolation.

Could you add an official end-to-end example that demonstrates:

• Next.js frontend
• FastAPI backend
• ai-python integration
• Streaming responses
• Tool calling

Many developers are building production AI applications with a Next.js frontend and Python backend, and an official full-stack reference implementation would help establish best practices and reduce integration effort.

[anbuzin]

@shloimy-wiesel we'll definitely make a Next.js example at some point when we reach a stable version. For now, there is FastAPI + VIte, that would be pretty much identical in terms of demonstrating the five points you highlighted.