release: cut v2.1.1

docs: simplify bilingual release notes

docs: remove outdated documentation

docs: refresh README preview screenshots

chore: disable config writes and remove frontend exports

feat: visualize auto-update status for v2.1.0

release: v2.0.0 sync README/UI/release notes

chore: final audit report and hardening tweaks

fix: update settings UX, token units, pricing auto, version stability

docs: cover non-systemd deployment

docs: add docker/container deployment guidance

feat: AI-friendly deploy doctor + update robustness

fix: token/cost calc, github fallback, panel hardening

feat: 添加日志屏蔽本地请求功能

feat: 实现稳定的请求统计持久化和清空功能