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)

docs/roadmap.md

@@ -3,7 +3,8 @@
 - mcp 管理器 ✅
 - i18n ✅
 - gemini cli
-- homebrew 支持
+- homebrew 支持 ✅
 - memory 管理
 - codex 更多预设供应商
 - 云同步
+- 本地代理