lore-server: Support file:// JWKS endpoints in JWK service

[kidskoding]

Summary

Fixes #32

Added a scheme check in fetch_new_keys() that checks for either file:// or http:// (https://)

• If http:// or https://, nothing changes - same network fetch as before
• If it's a file://, open the path on disk and read contents directly (implemented via tokio::fs::read_to_string instead of communicating over HTTP)

Test Plan

Added two tests covering the new file-read path: one verifies keys load correctly from a file:// endpoint and the other confirms a missing file still fails cleanly

• Ran Tests: cargo test -p lore-server auth::jwk:: — both loads_keys_from_file_url and file_url_missing_file_returns_error - PASS
• Format, Build, and Pre-commit - Formatted via clippy and cargo nightly formatter; Built via cargo build; pre-commit tool ran
  • cargo +nightly fmt --all
  • cargo clippy --all-targets -- -D warnings --no-deps
  • cargo build — all clean (no error)
  • pre-commit run --all-files — clean

[kidskoding]

maintainers / someone please review - @ragnarula @mjansson

[peter-lockhart-pub]

Thank you very much for the contribution, this looks good to me. Can I be a bit pedantic please; could you move the .gitignore change to another PR? Just so the commit remains meticulous and free from unrelated changes?

[kidskoding]

sure thing! accidentally stashed all changes at once!

[kidskoding]

@peter-lockhart-pub please review again, along with #50!

[peter-lockhart-pub]

Thanks!

[kidskoding]

Maintainers may need to reapprove CI/CD workflows due to a force push of commits on existing fork, intended to align with relevant PR titles - @mjansson, @peter-lockhart-pub

[peter-lockhart-pub]

Maintainers may need to reapprove CI/CD workflows due to a force push of commits on existing fork, intended to align with relevant PR titles - @mjansson, @peter-lockhart-pub

Done! This PR will be picked up by another process that will merge it now that it is approved and good to go