fix(clippy): resolve misc warnings across ML crates
- Implement Display trait instead of inherent to_string() (versioning.rs)
- Replace iter().nth() with .get(), .get(0) with .first()
- Collapse else-if chains, derive Default for enums
- Fix deref warnings, redundant let bindings, push_str('\n')
- Convert match-to-if-let, use saturating_sub, RangeInclusive::contains
- Replace vec![push;push] with vec![...] literal (feature_extraction.rs)
- Remove redundant redefinitions, unnecessary parentheses, casts
- Fix &Vec<_> to &[_] in function parameters
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
ccf9e22a55