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/loudness_backfill.go

@@ -13,15 +13,14 @@ import (
 	"git.fabledsword.com/bvandeusen/minstrel/internal/db/dbq"
 )
 
-// Loudness backfill (M464 #4995).
+// Loudness backfill.
 //
 // Every track is measured here, the new ones included: the scan only deletes a
 // changed file's measurement (see scanFile), and this worker measures it again.
-// Measuring inline in the scan was the first plan and was dropped, because the
-// analysis decodes the whole file. Added to the scan, a large import would run
-// several times longer and could pass StuckScanThreshold (1h), at which point
-// the run is reaped and a second scan started beside it. The fingerprint
-// backfill is a worker of its own for the same reason.
+// Not inline in the scan, because the analysis decodes the whole file: a large
+// import would run several times longer and could pass StuckScanThreshold
+// (1h), at which point the run is reaped and a second scan started beside it.
+// The fingerprint backfill is a worker of its own for the same reason.
 //
 // Until a track is measured it plays with no gain adjustment, which is how
 // every track played before normalization existed.
@@ -107,7 +106,7 @@ func (w *LoudnessBackfillWorker) Run(ctx context.Context) {
 }
 
 // runOnce contains a pass so that nothing it does (an error, a panic) can stop
-// the next tick from firing (rule 157).
+// the next tick from firing.
 func (w *LoudnessBackfillWorker) runOnce(ctx context.Context) {
 	defer func() {
 		if r := recover(); r != nil {
@@ -123,7 +122,7 @@ func (w *LoudnessBackfillWorker) runOnce(ctx context.Context) {
 			"processed", res.Processed, "measured", res.Measured, "silent", res.Silent,
 			"unreadable", res.Unreadable, "inconclusive", res.Inconclusive)
 	}
-	// Album loudness follows the tracks (#4996). It runs even with analysis
+	// Album loudness follows the tracks. It runs even with analysis
 	// switched off: it decodes nothing, and membership still changes as the
 	// library does.
 	albums, err := w.albumPass(ctx)