docs: library comments say what the scanner and resolver do, not how they came to be (#6277)

Rewrites the internal/library comment blocks to rule 32. Task, milestone,
decision and rule ids are gone; the incidents behind them are restated as
the constraint they left (why a file is deleted before its row, why the
missing mark is a mark, why duplicates block on duration). Counts and
album names from one library are dropped from production comments; test
comments keep the names their fixtures use. The tagReadVersion log keeps
each version's before and after, without the measurements.

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

internal/library/duplicate_settle_test.go

@@ -16,7 +16,7 @@ import (
 
 // undecidedSlot is one recording filed as Void and as Reach, two songs
 // MusicBrainz lists at lengths that cannot tell them apart, from a download
-// Minstrel imported: the resolver leaves it pending for the operator (#6184).
+// Minstrel imported: the resolver leaves it pending for an admin.
 func undecidedSlot(t *testing.T) (oneAlbumFixture, dbq.User) {
 	t.Helper()
 	f := newOneAlbumFixture(t, "acoustic", "Void", "Reach")
@@ -53,7 +53,7 @@ func emptiedTrack(t *testing.T, f oneAlbumFixture, id pgtype.UUID) bool {
 	return emptied
 }
 
-// settledByHand checks the group closed as the operator's and the audit row
+// settledByHand checks the group closed as the admin's and the audit row
 // names them.
 func settledByHand(t *testing.T, f oneAlbumFixture, actor dbq.User) {
 	t.Helper()
@@ -72,7 +72,7 @@ func settledByHand(t *testing.T, f oneAlbumFixture, actor dbq.User) {
 	}
 }
 
-// "Get it again": the operator cannot say which song the recording is, so
+// "Get it again": the admin cannot say which song the recording is, so
 // every copy goes, the download they came from is set aside, and both slots
 // wait for the album fetched again. A merge would have kept one title.
 func TestSettleWrongSlot_GetItAgainRemovesEveryCopy_Integration(t *testing.T) {
@@ -101,7 +101,7 @@ func TestSettleWrongSlot_GetItAgainRemovesEveryCopy_Integration(t *testing.T) {
 	}
 }
 
-// "This one is Reach": the copy the operator names stays, and only Void's slot
+// "This one is Reach": the copy the admin names stays, and only Void's slot
 // is emptied and wanted again.
 func TestSettleWrongSlot_KeepsTheCopyTheOperatorNames_Integration(t *testing.T) {
 	f, op := undecidedSlot(t)