Replaces var _ = func() pgtype.UUID { ... } with var _ map[pgtype.UUID]struct{}
which actually verifies map-key comparability, matching the comment.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Runs five SQL queries in parallel (recently added albums, most played
tracks, last played artists, rediscover albums, rediscover artists) via
goroutines with mutex-guarded first-error capture. Rediscover sections
merge primary + fallback results, de-duping by pgtype.UUID map key.
All HomePayload slices are non-nil so the API handler encodes [] not null.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
bvandeusen