docs: the history phrases the id sweep missed, restated as present-tense facts or traps (#6277)

A wider pass for "previous", "before the fix", "we shipped" and the
like. The chi double-subtree, uppercase Vorbis key and stopPropagation
comments now describe the trap they guard; commit hashes, CI run
numbers and a deleted file name are gone; uuidString's comment says
what it returns.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/playlists/scheduler.go

@@ -221,9 +221,8 @@ func (s *Scheduler) reconcile(ctx context.Context) {
 }
 
 // runStartupCatchUp fires BuildSystemPlaylists once for every active
-// user at startup, regardless of scheduled time. Matches the
-// behavior of the previous system_cron.go startup runOnce so users
-// whose scheduled fire was missed during downtime get caught up.
+// user at startup, regardless of scheduled time, so users whose
+// scheduled fire was missed during downtime get caught up.
 func (s *Scheduler) runStartupCatchUp(ctx context.Context, users []dbq.ListActiveUsersWithTimezonesRow) {
 	for _, u := range users {
 		s.rebuildUserDaily(ctx, u.ID, time.Now())