Image thumbnails can't be opened via keyboard

[felladrin]

Surfaced by a role-based review; verified against current code.

Problem: In client/components/Search/Results/Graphical/ImageResultsList.tsx, each thumbnail is a bare <img> with onClick and onKeyDown (Enter/Space) — but an <img> isn't focusable, so onKeyDown can never fire. Keyboard and switch users can't open the lightbox at all, and the handler gives a false impression of accessibility.

Fix: Make the thumbnail a real control (component="button" / wrap in UnstyledButton, or add role="button" + tabIndex={0}) with an aria-label from the title and a visible focus ring.

Files: client/components/Search/Results/Graphical/ImageResultsList.tsx

[11suixing11]

Hi, I can take a look at this.

I’ll keep the change scoped to the image thumbnail interaction: make thumbnails keyboard-focusable as real controls, preserve the existing lightbox behavior, and add a focused regression test for keyboard opening if the current test setup supports it.