docs: api comments say what the endpoints do, not how they came to be (#6277)

Rewrites the internal/api comment blocks to rule 32: task, milestone and
rule ids gone, the stories behind them restated as the constraint they
left, stale references corrected (the stream secret is wired from config,
the timezone handler already refreshes the scheduler, the Android app is
the native client, the design docs cited are not in the repo). Also
rewraps comment lines over 80 columns left by the earlier batches.

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

internal/api/notify_producers.go

@@ -11,7 +11,7 @@ import (
 	"git.fabledsword.com/bvandeusen/minstrel/internal/requests"
 )
 
-// Helpers for the handlers that produce notifications (M489). Every call is
+// Helpers for the handlers that produce notifications. Every call is
 // NotifyLogged: a notification never fails the action that caused it.
 
 // userLabel is how a user is named to someone else: their display name, or
@@ -74,7 +74,7 @@ func (h *handlers) trackLabel(ctx context.Context, trackID pgtype.UUID) string {
 }
 
 // notifyPlaybackErrors tells admins a track failed to play, naming it and who
-// it failed for (M542). The notice coalesces: while it is unread each report
+// it failed for. The notice coalesces: while it is unread each report
 // adds one to its count and its name to the front of the list.
 func (h *handlers) notifyPlaybackErrors(ctx context.Context, trackID pgtype.UUID, user dbq.User) {
 	p := notifications.Payload{Count: 1}