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/moved_test.go

@@ -12,8 +12,8 @@ import (
 )
 
 // fakeAdopter answers the audio-hash lookup only for the hash it holds, the way
-// the real query does. A fake that returned its rows for any hash could not tell
-// adoption by identity apart from adoption by coincidence.
+// the real query does. A fake that returned its rows for any hash could not
+// tell adoption by identity apart from adoption by coincidence.
 type fakeAdopter struct {
 	byMbid    []dbq.FindMissingTrackByMbidRow
 	hash      []byte
@@ -107,10 +107,9 @@ func TestAdoptMovedTrack_FallsBackToAudioHash(t *testing.T) {
 	}
 }
 
-// The case the old (file_size, duration_ms) pair got wrong: an unrelated file
-// that happens to share a size and a duration with a missing track. Size and
-// duration are no longer inputs at all; only the audio itself can match, and a
-// different recording has a different hash.
+// An unrelated file that happens to share a size and a duration with a missing
+// track is not adopted. Size and duration are not inputs at all; only the
+// audio itself can match, and a different recording has a different hash.
 func TestAdoptMovedTrack_DifferentAudioIsNotAdopted(t *testing.T) {
 	s := testScanner(t)
 	q := &fakeAdopter{hash: audioHash(0xAA), byHash: []dbq.FindMissingTrackByAudioHashRow{hashRow(1, oldPath)}, adoptRows: 1}
@@ -209,8 +208,9 @@ func TestAdoptMovedTrack_NoCandidates(t *testing.T) {
 	}
 }
 
-// The row's mark was cleared between lookup and update — another file adopted it
-// first. AdoptTrackPath's `missing_since IS NOT NULL` predicate reports 0 rows.
+// The row's mark was cleared between lookup and update — another file adopted
+// it first. AdoptTrackPath's `missing_since IS NOT NULL` predicate reports 0
+// rows.
 func TestAdoptMovedTrack_LostRaceReportsNotAdopted(t *testing.T) {
 	s := testScanner(t)
 	q := &fakeAdopter{
@@ -224,7 +224,7 @@ func TestAdoptMovedTrack_LostRaceReportsNotAdopted(t *testing.T) {
 }
 
 // Failing to detect a move must never fail the file: the caller falls back to
-// inserting a fresh row, which is the pre-#2528 behaviour.
+// inserting a fresh row.
 func TestAdoptMovedTrack_ToleratesQueryErrors(t *testing.T) {
 	sentinel := errors.New("db down")
 	tests := []struct {