GitLab

Resolves #1006

Endpoint role-checking was redundantly applied but FastAPI provides a nice abstraction mechanic...so I applied it. There should be no logical changes in this code; only simpler, cleaner ways for doing the same thing.

- Resolved an issue where header attributes Host, Authorization, Origin, and Referer were not being sanitized, resulting in two major issues:
  1. Ollama requests inadvertently exposed user information, leading to data leakage.
  2. When Ollama is deployed on different servers, and the intermediary proxy layer uses the host header to locate downstream services, it fails to find them.

Root Cause:
- In FastAPI, when accessing request.headers, all header names are converted to lowercase. This is because FastAPI, and its underlying framework Starlette, adhere to the HTTP/2 standard, which mandates lowercase header field names for performance and consistency.
- In HTTP/2, enforcing lowercase header field names reduces complexity in header processing as case sensitivity is no longer a concern. Thus, regardless of the case used in client-sent header fields, the server processes them uniformly in lowercase.
- This practice is adopted in FastAPI and other modern HTTP frameworks, even in an HTTP/1.1 context, to maintain consistency with HTTP/2 and improve overall performance. As a result, header field names are always presented in lowercase in FastAPI, even if the original request used capitalization or mixed case.

- feat: added new util to get the current user when needed. Middleware was adding authentication logic to all the routes. let's revisit if we can move the non-auth endpoints to a separate route.
- refac: update the routes to use new helpers for verification and retrieving user
- chore: added black for local formatting of py code