Closes the last deferred follow-up from #357. The library_changes
table is the append-only change log that drives /api/library/sync's
delta semantics — every mutation (scanner upsert, like, playlist
edit, track delete) writes one row. Without a retention policy the
table grows unbounded; the original migration (0025) called out the
follow-up explicitly.
New goroutine: sync.Compactor runs daily, deletes rows where
changed_at < now - 30 days. Logs a row count when non-zero so
operators can see compaction activity in the journal. First tick
fires on startup so a process that hasn't been compacted in a
while catches up immediately.
30-day retention matches the offline-mode spec
(docs/superpowers/specs/2026-05-09-flutter-offline-mode-design.md).
Clients with a cursor older than that hit the existing 410 fallback
path and resync from scratch.
Imported as syncpkg in main.go to follow the existing convention
(see internal/library/scanner.go).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
golangci-lint surfaced both on 9c7dec6:
- errcheck on bare 'defer tx.Rollback(ctx)' in 2 test files
- gofmt -s wanted tighter map-key alignment in library_sync.go +
library_sync_test.go (auto-fixed by 'gofmt -s -w')
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Wires sync.LogChange into the library mutation sites so /api/library/sync
reflects upserts and deletes.
Architectural pivot: LogChange's signature is now (ctx, dbq.DBTX, ...) so
it works with both *pgxpool.Pool and pgx.Tx. The scanner doesn't run
mutations in explicit transactions, so it pool-binds; delete.go matches.
Tx-bound callers (likes/playlists in subsequent commits) keep atomicity.
Also: sync.FormatUUID centralizes the pgtype.UUID → canonical string
conversion that both the scanner and the sync handler need; library_sync.go
now uses it instead of a local copy.
Best-effort logging on scanner failures (Warn, don't fail the scan): a
LogChange error after a successful upsert is rare and self-healing — the
next scan that touches the entity re-emits the change.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
New package internal/sync. LogChange writes a library_changes row inside
the supplied tx. Encode helpers produce stable composite ids for like_*
and playlist_track entries. Subsequent commits wire LogChange into the
scanner / likes / playlists services.
Also: dbtest.dataTables now includes library_changes so test isolation
holds across runs.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
bvandeusen