fix(reenrich): preserve release identity in batch actions

lib/utils/re_enrich_release_policy.dart

@@ -0,0 +1,8 @@
+enum ReEnrichOperationScope { singleFile, batch }
+
+/// A single-file action may deliberately repair a stale release identity,
+/// such as a playlist name stored in the album tag. Batch matching keeps the
+/// conservative album-mismatch guard because one false match has a much larger
+/// blast radius.
+bool allowsReleaseIdentityReplacement(ReEnrichOperationScope scope) =>
+    scope == ReEnrichOperationScope.singleFile;