PRs #738 and #644 committed their before/after review screenshots into the
repo (docs/a11y/focus-*.png, docs/a11y/login-*.png, docs/gallery-314-*.png).
Nothing references these files, so they only showed up as "random images" in
the doc folder (issue #1335). The README hero image and the feature preview
clips are referenced and are left untouched.
Add tests/test_docs_no_orphan_images.py to guard against recurrence: it fails
if any image under docs/ is referenced by no tracked text file.
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
