Harden Twitch panel beta flows and refine playlist UX

[Jamesllllllllll]

Summary

Hardens the Twitch panel beta flow, improves playlist/search UX, and adds better observability around extension request failures.

What Changed

• split the Twitch panel into one-time bootstrap plus a lightweight state endpoint with visible-tab polling, retry/backoff, and better reconnect handling
• reduced extension request load, added slow/error trace logging, and enabled invocation logs on both Workers for production diagnosis
• made VIP token consume/grant operations atomic and reconciled failure paths for viewer and moderator request changes
• refined playlist/search UX, including blacklist reason labels, version blacklisting from playlist management, and panel/settings polish for beta testers
• updated the Twitch panel rollout docs and local-test notes with Hosted Test rebuild/upload guidance

Related: #16, #18, #46

How To Test

1. Run npm run check:generated
2. Run npm run typecheck
3. Run npm run test
4. Build and test the hosted panel bundle with VITE_TWITCH_EXTENSION_API_BASE_URL=https://rocklist.live npm run build:extension:panel
5. Upload the new Hosted Test zip to Twitch and verify viewer, moderator, and broadcaster panel flows

Screenshots Or UI Notes

• Dashboard Settings now shows a simple Twitch extension beta install CTA instead of developer setup copy.
• Public and panel playlist/search surfaces show clearer blacklist reason labels and version-management affordances.
• The Twitch panel now handles loading/reconnect states more gracefully and polls a lightweight state endpoint instead of re-running full bootstrap.

Checklist

• I tested the change locally
• I updated docs or examples if needed
• I called out any follow-up work or known limitations

[github-actions]

Preview deployment updated.

App: https://request-bot-pr-52.jameskeezer.workers.dev
Frontend worker: request-bot-pr-52
Backend worker: request-bot-backend-pr-52