cargo fmt regroups; three clippy fixes:
- F-S-006: hoist MAX_API_KEY_CANDIDATES to module scope to satisfy
clippy::items_after_statements.
- F-S-009: use map_or instead of map().unwrap_or() per
clippy::map_unwrap_or.
- F-P-012: replace `|c| c.encode()` closure with the method itself
per clippy::redundant_closure_for_method_calls.
No behavior change.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>