Operator-flagged 2026-05-30 (round 2): the batched-loads change improved
consistency but still felt "chunky" — 5 items appeared together, then a
~200 ms API round-trip pause, then another 5. And infinite-scroll fired
too late when a single tall image (long manga page) made one masonry
column much taller than its siblings.
**Cadence (showcase store):**
- Fire all INITIAL_BATCHES fetches in PARALLEL — collapses the per-
batch round-trip gap so all the data arrives in ~1 RTT instead of 12
sequential RTTs.
- Trickle each response's items into images.value one at a time with
APPEND_DELAY_MS = 80ms between each (≈ the MasonryGrid stagger
animation, 70ms). User sees a smooth steady stream.
- fetchPage (the infinite-scroll path) uses the same trickle so its
5-item appends also cascade one-by-one instead of popping together.
- Sequence token guards against a fast shuffle / mount-then-shuffle
interleaving two trickles into the same images.value.
- Dropped useAsyncAction here — the parallel-fetch-then-trickle flow
doesn't fit its single-wrap-call shape cleanly; inline loading/error
state is clearer.
**Infinite-scroll trigger (MasonryGrid):**
- Pass `rootMargin: '2400px'` to useInfiniteScroll (was the 600px
default). The masonry sentinel sits at the bottom of the container,
whose height = MAX(column heights). A tall image in one column pushes
the sentinel ~2× viewport below where the user is actually reading
(the bottom of the SHORTER columns). 2400px ≈ 2-3 screen-heights of
pre-emptive trigger, comfortable for typical tall manga heights.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>