Fix Rapid Diffs image swipe view overlay alignment

Stanislav Lashmanovrequested to merge
slashmanov/rapid-diffs-fix-image-swipe-alignment into master

What

In Rapid Diffs image diffs, the swipe (and onion-skin) views overlay the old and new image frames. The shared image viewer container centers its content, so each frame's image centered on its own natural width instead of sharing a common edge — the frames did not overlay when the two images differed in size.

Left-aligns the frame images within the Rapid Diffs image container so both frames share the same edge.

Depends on !247832 (merged) (spec migration).

Re-enabled spec

  • user_creates_image_diff_notes swipe 'shows both images at the same position' (was skipped as a Rapid Diffs gap; now green).

The onion-skin 'resets opacity' example remains skipped (separate synthetic-drag flakiness, follow-up).

Reproduction

  1. Open an MR with a modified image on the Rapid Diffs Changes tab.
  2. Switch to Swipe view — the old and new images now overlay on the same edge.

Merge request reports