Harden item occurrence grounding

internal/modules/dnd/locations/identity/identity.go

@@ -10,8 +10,7 @@ import (
 
 	"gitea.maximumdirect.net/eric/notarius/internal/core/source"
 	"gitea.maximumdirect.net/eric/notarius/internal/modules/dnd"
-	"golang.org/x/text/cases"
-	"golang.org/x/text/unicode/norm"
+	"gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/shared"
 )
 
 const (
@@ -51,17 +50,7 @@ func NormalizeDisplay(value string) string {
 
 // ComparisonKey returns the stable key used for location identity comparisons.
 func ComparisonKey(value string) string {
-	value = norm.NFKC.String(value)
-	value = strings.Map(func(r rune) rune {
-		switch r {
-		case '\u2018', '\u2019', '\u02bc':
-			return '\''
-		default:
-			return r
-		}
-	}, value)
-	value = strings.Join(strings.Fields(value), " ")
-	return cases.Fold().String(value)
+	return shared.ComparisonKey(value)
 }
 
 // DeriveID derives a location ID from name and the earliest canonical evidence

internal/modules/dnd/locations/identity/identity_test.go

@@ -15,17 +15,6 @@ func TestNormalizeDisplayOnlyChangesWhitespace(t *testing.T) {
 	}
 }
 
-func TestComparisonKeyNormalizesUnicodeWhitespaceAndApostrophes(t *testing.T) {
-	for _, pair := range [][2]string{
-		{"  Caf\u00e9\u2003d\u2019Or  ", "cafe\u0301 d'Or"},
-		{"\uff34\uff48\uff45\u00a0\uff34\uff41\uff56\uff45\uff52\uff4e", "the tavern"},
-	} {
-		if left, right := ComparisonKey(pair[0]), ComparisonKey(pair[1]); left != right {
-			t.Fatalf("ComparisonKey(%q) = %q, want value equal to %q", pair[0], left, pair[1])
-		}
-	}
-}
-
 func TestDeriveIDUsesDocumentedCompactJSONInput(t *testing.T) {
 	refs := []source.SourceRef{
 		{SourceID: "session-alpha", StartUnitID: 9, EndUnitID: 9},