- Add auto_rename_untitled Rust command: one-shot rename of untitled-* files based on H1 heading, with collision handling (-2, -3) - Wire auto-rename into frontend save flow (useAppSave.ts) - Update Rust tests: extract_title now uses H1 > frontmatter > filename - Add extract_h1_title tests Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>