Improve D&D registry normalization efficiency

internal/modules/dnd/normalize/itemregistry/normalizer_test.go

@@ -85,6 +85,20 @@ func TestNormalizeConsolidatesEqualNamesAcrossEvidenceWithoutMutation(t *testing
 	}
 }
 
+func BenchmarkComparisonNameGroupsManyDistinct(b *testing.B) {
+	records := make([]normalizedRecord, 1_000)
+	for index := range records {
+		records[index] = normalizedRecord{item: dnd.Item{Name: "Item " + strconv.Itoa(index)}}
+	}
+	b.ReportAllocs()
+	b.ResetTimer()
+	for iteration := 0; iteration < b.N; iteration++ {
+		if groups := comparisonNameGroups(records); len(groups) != len(records) {
+			b.Fatalf("group count = %d, want %d", len(groups), len(records))
+		}
+	}
+}
+
 func TestNormalizeAppliesSafeAliasProposal(t *testing.T) {
 	doc := semanticDocument()
 	input := dnd.ItemRegistry{Items: []dnd.Item{