[Qiyuanqiii]

Summary

Agent Browser screenshots were limited to a 320px-high thumbnail, making page text hard to inspect. Click View original to use the existing image viewer: fit or 100% size, zoom, copy PNG and download the original. The viewer uses the already verified bytes and closes when the screenshot, browser session or Run changes; Escape returns focus to the thumbnail.

Built on #432 (Qiyuanqiii/docs-current-state); this PR changes only the screenshot UI, its tests and visual evidence. It adds no browser permissions or API routes.

Real before/after screenshots

The same screenshot from the production browser tools and Go API, in the baseline and changed production frontend. Captured in Edge on Windows. Verification notes.

Before	After

480 × 600 window

Validation

• Agent Browser component: 21 tests passed; existing image-viewer suite: 8 tests passed.
• npm run build — TypeScript and production Vite build.
• Actual browser: open, 100%, fit, clipboard PNG, original download, Escape focus return and 480 × 600 layout.
• Downloaded bytes match the server SHA-256; copied image retains 1258 × 802 dimensions.
• git diff --check.

CI will run the repository-wide checks. Local verification is scoped to the frontend change.

Surface governance

• No Surface is added, promoted, downgraded, deprecated, or removed.
• Registry item(s): N/A — no Surface change.

Audit

• No credentials or local runtime data are included; screenshots use the owned journey test page.
• Existing verified-image loading and browser authority boundaries are preserved.
• Behavior and verification are recorded in the acceptance README.

Screenshot download recovery

A failed first screenshot request now has a Reload screenshot action. It retries the same verified image without issuing browser controls. A new regression failed before the fix; a real Edge run with one interrupted image request confirmed recovery and reopening the original viewer.

Failed request before	Failed request after

最新提交 ba0eafa631bb98f79cde0f9b41fc663bb3191f08 的 完整 CI 已通过：23 项成功，0 失败、0 等待。