Formatting was configured but never enforced: `bun run format:check`
reported 199 unformatted files and ran in no workflow and in no git hook,
so .prettierrc (printWidth 100, trailing commas) described an intention
rather than the tree.
This is the one-time sweep that makes the check gateable. Whitespace and
token-reflow only -- no behavioural change: `bun run check` reports 0
errors and all 1053 frontend tests pass before and after.
Kept out of every other commit on purpose. A 199-file diff mixed with
real changes is unreviewable, and the next commit turns format:check
into a hard CI gate so this cannot silently accumulate again.
The library overview and the home shortcut strip showed artwork of three
different shapes — square music covers, 16:9 library backdrops, 2:3 posters —
in grids that pick one box and crop everything to it. The home strip said so
in a comment: it forced `aspect="video"` on music libraries so the row would
line up, which lined it up by cutting the covers down.
Both surfaces are now justified mosaics: rows share one height and each tile is
as wide as its own artwork. `layoutMosaic` is a pure module — it packs tiles
until the height needed to fill the container drops to the target, justifies the
row by absorbing the rounding remainder into its widest tile, and deliberately
leaves the last row unstretched so one leftover tile does not inflate into a
banner. The component supplies only what the DOM knows: the measured container
width, and the artwork's *decoded* aspect ratio (via a new `onNaturalSize` on
CachedImage), committed in one debounced batch so the grid does not reshuffle
once per image as artwork lands.
Favourites gain a tile per category beside the library it belongs to, alongside
the existing cross-library entry. Which collection type maps to which category
is Jellyfin vocabulary, so it is derived in Rust — `SearchScope::for_collection_type`,
stamped onto every `Library` by a new constructor and carried over as an optional
`favoritesScope`. Deriving it in Svelte would have rebuilt the exact leak
`SearchScope::item_types` was extracted to close. A category shows one tile
however many libraries share it, and a library kind favourites do not carve up
(Live TV, channels, books) gets none.
Also corrects the requirements-count test, which the UR-074 commit left one
behind.
Spec: docs/specs/library-mosaic.md
TRACES: UR-075, UR-067 | DR-163, DR-164 | UT-158..UT-162