A full page at the cap is not proof of truncation, so a library whose
size is an exact multiple of the page size failed for no reason. Each
paged loop now keeps going one page past the cap and only throws when
that page comes back non-empty; a library up to the cap syncs normally.
Add a boundary test for the exact-cap case.
Also note the accepted per-batch observer invalidation churn in the sync
code and the architecture doc.
- Paged loops now throw when they hit maxPages with a full last page, so a
truncated enumeration aborts the entity's collect and skips its prune
instead of deleting rows the sync never saw. The cap is injectable for
tests.
- Move sync serialization into SyncManager (tryLock coalesces duplicate
requests) and construct SyncService there; SourceRepository only exposes
the active MusicSource. Removes the repo <-> sync import cycle.
- Re-throw CancellationException instead of reporting a cancelled sync as
failed.
- Add buffer(1) to the outer albums/songs/playlistSongs flows so their
flowOn channel cannot hold 64 batches.
- Rank prefetch is best-effort (missing frequent/recent no longer aborts
the album sync).
- Skip playlist entries without an id, keeping positions contiguous.
- Chunk stale-disc deletes like the other prunes.
- Update the implementation plan line that still described the old
single-transaction sync.
adds docs/architecture.md (stack, layers, data model, sync, search, networking, testing, CI), docs/implementation-plan.md (phases and status), and AGENTS.md for agents and contributors