fix: resolve Phase 2 review issues (needless_borrow, formatting, doc comment)
- Remove needless borrow: change &relay to relay at oauth.rs:470
* relay is already &RelayClient from state.relay_client()
* Passing &relay created &&RelayClient, now corrected
- Fix formatting violations in lib.rs and oauth.rs
* cargo fmt corrects line breaks in oauth.rs:44-46
* cargo fmt corrects line breaks in lib.rs:339-346
* cargo fmt corrects line breaks in lib.rs:556-559
* cargo fmt corrects line breaks in lib.rs:605-608
- Update check_handle_resolution doc comment (lib.rs)
* Previous doc said "Never rejects" but return type is Result<bool, String>
* Updated to clarify: "Returns Result for Tauri IPC compatibility, but never returns Err"
* Matches actual behavior where network errors return false, not Err