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/sync/compactor.go

@@ -1,15 +1,12 @@
-// Periodic compactor for the library_changes log (#357 deferred
-// follow-up). Every mutation in the library writes one row, so the
-// table grows unbounded without a retention policy. This worker
-// trims rows older than CompactorRetention on a daily tick.
+// Periodic compactor for the library_changes log. Every mutation in the
+// library writes one row, so the table grows unbounded without a retention
+// policy. This worker trims rows older than CompactorRetention on a daily
+// tick.
 //
-// Why daily / 30 days: Flutter clients track a per-app cursor and
-// pull deltas from the last seen id. As long as a client checks in
-// at least once per retention window, it never sees the cursor go
-// stale. Clients that drop offline longer than that hit the /api/
-// library/sync 410 fallback and do a full resync. 30 days is the
-// established norm for similar offline-cache delta logs and matches
-// the spec at docs/superpowers/specs/2026-05-09-flutter-offline-mode-design.md.
+// Why 30 days: clients keep a cursor and pull deltas from the last seen id.
+// A client that checks in at least once per retention window never sees its
+// cursor go stale; one offline longer than that gets the /api/library/sync
+// 410 and does a full resync.
 
 package sync