chore(release): prepare for v3.6.1 release
- Bump version to 3.6.1 across all config files
- package.json, Cargo.toml, tauri.conf.json
- README.md and README_ZH.md version badges
- Auto-updated Cargo.lock
- Add release notes documentation
- docs/release-note-v3.6.0-en.md (archive)
- docs/release-note-v3.6.1-zh.md (cumulative format)
- docs/release-note-v3.6.1-en.md (cumulative format)
- Enlarge PackyCode sponsor logo by 50% (100px → 150px)
- Update roadmap checklist (homebrew support marked as done)
Jason