The twin of the previous commit, with a sharper consequence. `decorative`
does not merely describe the previous image, it *exempts* it:
`validate-working-copy.ts`'s EVIDENCE_ALT_REQUIRED reads
`Asset.decorative`, so a flag inherited from a discarded divider lets a
meaningful diagram publish with no accessible name at all -- the check
passes rather than catching it. Stale alt text ships a wrong description;
stale `decorative` ships none.
Same terminal-state retry path: tick 장식용 for `divider.png`, have it
rejected, pick `sequence.png`, upload -- and `sequence.png` shipped as
decorative with `altText: undefined`.
Resetting it also re-enables the alt input, so the post-selection focus
call no longer has to ask whether it would land on a disabled control.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
