Visual regression baselines need regenerating after the MDXEditor dark theme fixes
## Problem/Motivation
The visual regression tests now fail. The rendered output of the MDXEditor changed when the Gin dark theme rendering was fixed in #3582474 (and the related Tool Explorer dark theme fix #3582473), so the committed baseline screenshots no longer match the current, correct output.
These are expected diffs — the UI legitimately changed — not a regression. The stored baselines are simply stale.
## Proposed resolution
Regenerate the visual regression baselines against the current MDXEditor rendering (light and dark theme) and commit the new reference images, so the suite passes on the corrected output.
## Remaining tasks
- Regenerate the baseline screenshots for the affected UI elements.
- Verify the diffs correspond only to the intended dark theme changes from #3582474 / #3582473.
- Commit the updated baselines.
## Related
- #3582474 — MDX Editor does not render correctly with Gin dark theme (fixed)
- #3582473 — Tool Explorer does not render correctly with Gin dark theme (fixed)
- #3586461 — Add non-required visual regression tests for the four built UI elements
issue