Capture the preview/browser iframe DOM with snapDOM (html-to-image
fallback) so web annotation screenshots match the visible viewport,
without a headless Chromium dependency.
- Preserve document scroll via viewport crop and re-bake nested scroll
(e.g. the Starlight sidebar) deterministically on the clone
- Pin position:fixed elements to their measured viewport rect so headers
and sidebars land correctly in the crop
- Extract preview capture/proxy helpers into
lib/preview/screenshot-capture.ts to slim down ContextPanel
- Guard the external preview proxy against SSRF to private, loopback and
reserved/link-local addresses (incl. cloud metadata)
- Fully validate preview bridge messages before formatting/use
- Warn on the empty browser tab that pages run with full access, so
users browse untrusted sites knowingly
Bohdan Triapitsyn