docs: server comments say what the code does, not how it came to be (#6277)

Comment blocks in cmd/minstrel and 30 smaller internal packages, rewritten
to rule 32's standard with each citation read in context: task, milestone
and rule ids go, and so do the stories they were attached to ("used to",
"Before #N", measurements from one install, quotes, pointers to Fabled
Librarian's records and to docs/superpowers files that are not in the
repo). Where a story wrapped a real constraint, the constraint stays as a
present-tense fact.

Comments that had gone stale are corrected:
- taste.Config: the tuned values are overlaid by internal/recsettings;
  it is no longer "a later follow-up".
- StorageConfig: the data dir holds art, caches and the stream secret,
  not only playlist covers.
- the Subsonic album list and getUser comments describe what they do
  today rather than a milestone that would change it.

Checked: the non-comment token stream of every changed file matches
HEAD, and gofmt -l is empty.

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

internal/notifications/digest.go

@@ -15,10 +15,8 @@ import (
 	"git.fabledsword.com/bvandeusen/minstrel/internal/mailer"
 )
 
-// The email digest (#5346). Nothing is emailed per event. Operator,
-// 2026-10-08: "music and stuff coming in should land as a summary email and
-// not everytime same for a approvals the emails should be grouped by a
-// reasonable amount of time like an hour or so."
+// The email digest. Nothing is emailed per event: a steady stream of new
+// music or approvals would otherwise be a stream of emails.
 //
 // - EmailSummary kinds (new music) go out at most once a day, at the summary
 //   hour in the user's own timezone, listing everything since the last one.