release: apply final roster correction to preview

[lidge-jun]

Summary

Bring the pre-publication roster cache correction from #3931 into preview. The main roster keeps its own fresh discovery list; fallback availability is used only for fallback controls. No version change and no sponsor placement.

The owner authorized these release promotions. Depends on #3931 landing in dev; the prepared tree matches its candidate except the channel version.

Verification

• Three-file source correction with stale-cache/fallback-failure regression scenarios.
• Local suites/typechecks/builds/installs NOT RUN per owner; hosted CI only.
• Previous regression repairs passed independent Astra review; this follow-up receives independent source re-review and fresh hosted checks.
• Publication still requires this final promotion SHA's push CI, service lifecycle and all-lanes Windows/macOS control verification, then release dry-run.
• Expected enforce-target wrong-base is the previously declared owner-authorized release promotion exception; it is not reported as passing and no policies are disabled.

GUI layout unchanged; earlier mocked workspace failure-state evidence:

Checklist

• Scope stays focused and avoids unrelated cleanup.
• Docs or release notes were updated when needed.
• Security-sensitive changes were reviewed for secrets, auth, and unsafe defaults.

[coderabbitai]

Important

Draft PR not reviewed

Draft PRs are not automatically reviewed by default.

• Trigger a manual review

To automatically review draft PRs, update your CodeRabbit configuration:

reviews:
  auto_review:
    drafts: true

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}

[github-actions]

✅ Deterministic PR hygiene checks passed.

[github-actions]

⏳ DRAFT

• wrong target branch (preview); retarget to dev.

What to do

• Retarget this PR to dev — all contributions go to dev.

Its title has been prefixed with [WRONG BRANCH].
This pull request was already a draft. Its draft status will be preserved after every issue above is resolved.

Hygiene

✅ Deterministic PR hygiene checks passed.

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-09-07T17:36:53.392574Z	80b1f52	Draft marked ready

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review" or "@codex security review".

Codex reacts with 👀 while any review is running, comments if it has suggestions, and reacts with 👍 once all reviews finish with no findings.