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/auth/setup.go

@@ -7,10 +7,10 @@ import (
 )
 
 // SetupToken guards the first-admin registration. Until the first account
-// exists, register makes whoever calls it the admin, so a fresh instance on a
-// public address belonged to whoever found it first. Now that call also has
-// to carry this token, which is generated at startup and written only to the
-// server log: proof that the caller can read the operator's logs.
+// exists, register makes whoever calls it the admin, so without this a fresh
+// instance on a public address would belong to whoever found it first. The
+// call must carry this token, which is generated at startup and written only
+// to the server log: proof that the caller can read the server's logs.
 //
 // The token lives in memory. A restart mints a new one and logs it again,
 // which is the behaviour wanted: an old token from a log line someone else