Show a todo list the item a search found it by

[vmillet-dev]

Closes #117.

#35 gave every card the line that put it in the results. Every card except a todo
list, where the branch is unreachable:

@if (isChecklist())        → progress bar + the item layer
@else if (snippetIsCode()) → the excerpt, coloured
@else                      → the excerpt, as prose

And the items shown were picked without consulting the search: items.slice(0, 2).
So a list that matched on its fifth item showed its first two and +3 more.

A window, not a replacement

⚠️ Rendering the excerpt instead was not an option. .card-items is a sibling
layer carrying real checkboxes — a card can be ticked without opening it, and
07-checklists drives that. The window of visible items slides to the match
instead: same order, same boxes, the card simply scrolled to the right place.

The tags do the same, so a note found by its third tag shows that tag rather than
its first two.

The trap that would have lost data

The template counts within the window; the position written back is the one in
the note. They were the same number while the window always started at zero. With
it sliding, ticking the first visible box would have ticked the first item of the
list — a card silently editing a line the user never saw.

onItemToggle offsets by the window start, and there is a test on it in both
suites. Checked by removing the offset: red in the unit suite.

Finding the item behind a clipped excerpt

The excerpt is cut at 160 characters and gains a trailing …, so a long item never
equals its own text. Matched on the prefix, with a test.

Checked locally

npm test 980 passing, npm run lint clean, npm run test:e2e 15/15 in 4:15.

🤖 Generated with Claude Code