fix: address code review findings

internal/normalize/normalize_test.go

@@ -39,6 +39,11 @@ func TestNormalizeString_Basic(t *testing.T) {
 		// Year-only title is preserved (not collapsed to empty) so it can still match
 		{"1989", "1989"},
 		{"2112", "2112"},
+		// A year-plus-suffix title collapses to empty: it is a distinct release
+		// group (e.g. "1989 (Deluxe)") and must NOT match a bare "1989".
+		{"1989 (Deluxe)", ""},
+		{"1989 [Deluxe Edition]", ""},
+		{"2112 (Remastered)", ""},
 	}
 
 	for _, tt := range tests {