[Improve] Catch visual inconsistencies in UI proof

[roomote-community]

Opened on behalf of sky. Follow up by mentioning @roomote, in the web UI, or in Discord.

Related issue

Not linked; this is an internal maintainer-requested improvement.

Why this PR exists

Visual proof could satisfy a narrow artifact claim while overlooking an obvious defect elsewhere in the captured frame, such as a dark component rendered against a light-themed page.

• A maintainer explicitly invited this PR in the linked issue or discussion
• I am a maintainer / this is internal Roomote work

What changed

• Require proof-runner self-review to inspect both the claimed focal state and the entire captured frame before upload.
• Check for theme inconsistency, contrast, clipping, broken layout, unintended loading or error states, and styling that conflicts with surrounding UI.
• Retry capture-caused failures once, but block successful proof when the implementation itself is visually wrong.
• Cover the expanded self-review contract with a focused prompt regression test.

This makes UI proof stricter and prevents visually inconsistent screenshots from being presented as successful evidence.

How it was tested

• Ran the focused proof-runner prompt test.
• Ran worker type checking and formatting checks.
• Passed the repository pre-push lint, fast type-check, and unused-code gates.

Checklist

• The PR title follows the repo convention: [Fix], [Feat], [Improve], [Refactor], [Docs], or [Chore] followed by a user-facing description
• This PR is small and scoped to one change
• pnpm lint and pnpm check-types pass locally
• I added tests or included a clear manual validation note above
• I removed secrets, tokens, private keys, and customer data from code, logs, and screenshots
• If this change should appear in the changelog, I ran pnpm changeset

[roomote-community]

No code issues found. See task

_{Reviewed 8e4a606}

[github-actions]

All contributors have signed the CLA.
_{Posted by the CLA Assistant Lite bot.}

[easonLiangWorldedtech]

I have read the CLA Document and I hereby sign the CLA