Images in an html_render block cannot be browsed in the image viewer #25574

Before submitting

• I searched existing issues and did not find a duplicate.
• I included enough detail to reproduce or investigate the problem.

Area

apps/web

Steps to reproduce

1. Ask an agent for an html_render page with three sibling <img> elements inside one <div>.
2. Click the middle image.
3. To compare the other two, close the viewer and click each one again.

Expected behavior

Clicking any image of a block opens the block in the viewer, and the reader can move through it with the arrow keys or prev/next without closing the dialog.

Actual behavior

The viewer opens with that single image only. There are no arrows and no way to reach the other images of the block, so comparing a row of screenshots means closing and reopening the viewer once per image.

Impact

Minor bug or occasional failure

Version or commit

main at b424c6e

Environment

T3 Code (desktop/web), macOS, current dev build.

Logs or stack traces

None. The viewer already accepts a gallery ({ images, index }); what limits it is the iframe bridge in packages/shared/src/htmlRender.ts, which posts a single { src, name } from the injected page script.

Screenshots, recordings, or supporting files

Not attached yet; a viewer screenshot is coming in the comments.

Workaround

Close the dialog and click the next image, once per image.