The browser verification this note asked for has been done — not with a
hand-rolled Playwright script but with the official Chrome DevTools for
agents (chrome-devtools-mcp@1.8.0, --categoryExtensions=true) against
the real MV3 build (npm run build:extension, unpacked install, pinned ID
gaclgcfljpjojddiikddejenlnjaggie).
Every item on the original checklist passed, plus persistence and console checks (24/24):
- Unpacked extension installed via
install_extension— pinned ID confirmed. - Opened
https://x.com/and triggered the toolbar action; the real popup was snapshotted and screenshotted. - Bottom-nav language control showed EN initially.
- Switching to Chinese flipped all visible text, including the dynamic status card ("X 页面 已就绪 / 引用、长文及媒体恢复功能已激活。").
- Close + reopen: Chinese persisted (
chrome.storage.localuiLang). - Switched back to English; English text returned.
- Popup and service-worker consoles were clean of SourceCapsule errors.
- Bonus: the strict-export toggle was switched off and its persistence into
the X page's
sourcecapsule.prefslocalStorage was verified after reopen.
The repeatable procedure now lives in docs/extension-acceptance.md, and the
automation is npm run accept:extension (scripts/accept-extension.mjs).
BURNDOWN.md no longer claims agents cannot exercise the popup.
Remaining manual-only item: the File System Access folder picker (a real native dialog cannot be driven from DevTools automation).