The Lightbox renders `.lightbox-text-scroll` while the text loader is still
`loading` (Lightbox.svelte ~2698), and openMarkdown waited only for that card.
When the body was late, the scroll leg's single wheel landed on an empty,
unscrollable card and scrollTop stayed 0 (2 first-attempt failures in 82 CI E2E
jobs). openMarkdown now waits for `.lightbox-text-body`, which exists only in
the `ready` phase, and the scroll leg asserts its premise that the card
overflows.
Control: the text body fetch delayed 1.5s by a route fails the scroll leg 10/10
with CI's signature without the wait, and passes 10/10 with it. Unforced, the
whole spec x40 at 8 workers passes 160/160.
Claude-Session: https://claude.ai/code/session_01NidgPePY7UvHcEJCMkD2Qz
xarmian
69272256cd