The v4 bump moved the PostCSS plugin to @tailwindcss/postcss, breaking
the production build while the project still uses a v3-style
tailwind.config.ts and @apply components.
- add feishu_links D1 table and link store helpers
- implement X-Lark-Signature verification, url_verification, /gh login|logout|comment|merge|close and card.action.trigger Merge/Close
- render interactive cards with clickable title link, inline links and callback buttons (no whole-card card_link)
- bind Feishu account in OAuth callback
- document event subscription and required scopes
wrangler@4.118 requires @cloudflare/workers-types@^5, so a fresh
`npm install` (Cloudflare Workers Build CI) failed with ERESOLVE against
the old ^4 pin. Align to ^5; typecheck, lint and tests still pass.