Put middleware files into a middleware directory

What is the technical debt you think should be addressed?

Right now, the structure is:

tree src/llama_stack/core/server 
src/llama_stack/core/server
├── __init__.py
├── auth_providers.py
├── auth.py
├── fastapi_router_registry.py
├── quota.py
├── routes.py
└── server.py

To make it more explicit, these:

• quota.py
• auth.py
• auth_providers.py

Could be in a src/llama_stack/core/server/middleware directory.

What is the benefit of addressing this technical debt?

Easier to identify when glancing at the repo structure.

Other thoughts

No response