feature: using no GIL or Granian to improve router performance

Describe the feature

We can potentially use Python with No GIL or the Granian HTTP server to improve router performance, throughput, and concurrency.

Why do you need this feature?

1. Python No GIL: Python 3.13 introduces the possibility to run Python without the GIL. Removing the GIL can drastically improve concurrency in CPU-bound or mixed CPU-/I/O-bound workloads. A few references that show the potential performance gains:

• “Python 3.13 Without the GIL: A Game-Changer for Concurrency”
• “Python GIL vs. NoGIL: Boost I/O performance 10x with one line change”
  Adopting a No GIL variant of Python can improve the router’s concurrency, especially under heavy traffic.

2. Granian
   Granian is a Rust HTTP server for Python applications. By using Granian as a router backend, we can potentially reduce latency and increase throughput.

Additional context

No response

Start by measuring the current router under representative CPU-bound, I/O-bound, and heavy-traffic workloads, then compare Python 3.13 No-GIL and Granian as separate options. Done means the project has reproducible benchmark results and a decided implementation direction, with the affected entry points and validation steps identified.