fix: Claude Code session recovery, structured output bridge, no-tool …

…drift detection (cherry-picked from PR SleepingBag945#1 by majorcheng)

feat: dashboard account add/delete, quick start README, CI release wo…

…rkflow

- Add account via token_v2 paste in Dashboard (auto-discover user info, models)
- Delete account from card with confirmation dialog
- Backend endpoints: POST /admin/accounts/add, POST /admin/accounts/delete
- Restructure README (EN/CN): Quick Start at top, concise setup
- Add GitHub Actions release workflow (linux/darwin/windows, amd64/arm64)
- Updated frontend build with new UI components