Document mirror maintenance for legacy manifests

Author: Copilot

AGENTS.md

@@ -102,7 +102,8 @@ The shared root marketplace must stay dual-compatible: use repository-root-relat
 plugin `source` paths and preserve legacy `category`/`tags` fields alongside Open
 Plugins metadata. Existing marketplace subscriptions may still resolve the legacy
 paths during auto-update, so removing or drifting these files can force users to
-reinstall. Run
+reinstall. Because mirrors are committed files (not symlinks), update both source
+and legacy copies together, then run
 `node scripts/validate-legacy-compatibility.js` after metadata changes.
 
 ## Code Conventions

scripts/validate-legacy-compatibility.js

@@ -3,7 +3,9 @@
 /**
  * Validates that legacy .claude-plugin manifests mirror the Open Plugins
  * metadata. Existing marketplace subscriptions still resolve the legacy paths
- * during auto-update, so these files must stay in sync.
+ * during auto-update, so these files must stay in sync. Mirrors are committed
+ * files (not links), so this guard must pass whenever marketplace/plugin
+ * metadata changes.
  */
 
 const fs = require('fs');