End-to-end pilot of the per-item architecture. Home now reads from
the new homeIndexProvider (drift-first over CachedHomeIndex with
/api/home/index discovery + SWR), then each tile is a small
ConsumerWidget watching its own albumTileProvider/artistTileProvider/
trackTileProvider. Tiles render a matched-dimension skeleton while
their entity is still hydrating, and swap in the real card once
drift emits the populated row.
Track hydration is wired up — /api/tracks/:id already existed so
the queue's case 'track' just calls api.getTrack(id) and persists.
The visible behavior:
* Cold visit: small /api/home/index round-trip (IDs only, ~10×
smaller than /api/home), then sections appear shaped with
skeleton tiles; each tile materializes as the hydration queue
drains. No more "30s blank → everything pops in at once."
* Warm visit: drift index emits instantly, drift entity rows emit
instantly, no network. Page paints fully in the first frame.
* Mid-state: scrolling through a partially-hydrated section sees
real cards next to skeleton cards. Layout doesn't shift because
skeletons match real-card dimensions exactly.
CachedHomeSnapshot (and the legacy homeProvider) stay in place but
unconsumed by Flutter — left in for now so revert is cheap if the
new path needs reworking. Cleanup follow-up in a later slice.
Old /api/home endpoint untouched, so the web client keeps working
unchanged.
Slice A landed with three transitive imports that the analyzer
correctly flagged as unused. AppDb / CachedAlbums table refs
propagate through audio_cache_manager.dart's `show appDbProvider`
re-export chain so the explicit db.dart import in the consumers
is redundant.
Plumbing for the per-item rendering pass — no UI changes yet, just
the layers the home/playlist/liked migrations will sit on.
* CachedHomeIndex drift table (schema 5→6) — section/position →
entity-id rows, populated by the upcoming /api/home/index endpoint.
* HydrationQueue (concurrency=4, in-flight dedup) — bounded request
pump that takes (entityType, entityId) and persists the result to
the right cached_<entity> table. Albums + artists wired today;
tracks deferred until /api/tracks/:id exists.
* Per-entity tile providers (albumTileProvider, artistTileProvider,
trackTileProvider as StreamProvider.family) — watch drift, enqueue
hydration on miss, yield AsyncValue<EntityRef?>.
* Skeleton widgets (album/artist/track) matched to the real card
dimensions with a 1.2s shimmer sweep using FabledSword tokens. No
shimmer-package dep — single AnimationController per surface.
See docs/superpowers/specs/2026-05-13-per-item-rendering-design.md
for the full architecture rationale.
bvandeusen