chore: bump version to v3.5.0 and update roadmap

Version Changes:
- Update version to 3.5.0 in package.json, Cargo.toml, and tauri.conf.json

Changelog Updates:
- Add v3.5.0 release notes with comprehensive feature list
- Document MCP management system implementation
- Document configuration import/export functionality
- Document endpoint speed testing feature
- List all improvements, bug fixes, and technical enhancements

Roadmap Updates:
- Mark MCP manager as completed ✅
- Mark i18n (internationalization) as completed ✅
- Add new planned features: memory management, cloud sync
- Reorganize feature priorities

package.json

@@ -1,6 +1,6 @@
 {
   "name": "cc-switch",
-  "version": "3.4.0",
+  "version": "3.5.0",
   "description": "Claude Code & Codex 供应商切换工具",
   "scripts": {
     "dev": "pnpm tauri dev",