A list pays per row, and only while scrolling — and none of this is
visible to any test tier: nothing renders differently and nothing
fails, the app is just slower.
- The track list's Art column rendered `CoverArtPath`, the original
artwork, into a 24 px box while `CoverArtSmall` sat unused on the
same model, with no `loading="lazy"`. 26 of 26 image requests asked
for the full-size tier; now 0.
- `artists-view`'s avatar fallback linear-scanned every cached album
per card per frame, lowercasing two strings per comparison, inside
the virtualizer's renderItem — the common case, since a locally
tagged library has no artist images at all. Measured at 5 000 albums
and 24 visible cards: 1.46 ms/frame -> 0.01 ms/frame.
- Five components resolved selected file paths back to tracks with
`tracks.find(...)`; they share `utils/track-index.ts` now. "Select
all -> Edit tags" at 50 000 tracks: 3 051-6 298 ms -> 68 ms.
- "Play this artist", "play these albums" and the album drag cache
resolve paths in one call instead of one per album.
- The column-resize drag registers its document listeners on mousedown.
Two things here are load-bearing and read as sloppiness. The per-render
arrow functions in `artists-view` and `genres-view` are the *only*
thing changing a property of their virtualizer on a host update, and
therefore the only thing repainting the cards: hoisting them to stable
fields takes a selection from 1 highlighted card to 0. And a row inside
a virtualizer needs `width: 100%`, because the virtualizer positions
its children absolutely and a grid row otherwise shrinks to fit its
content and stops lining up with the header above it.