fix(management): harden marketplace state transitions

- detach verified shared symlinks when a profile is reopened as bare

- prune stale marketplace entries whose payload directories no longer exist

- add regressions for bare/non-bare transitions and stale registry recovery

src/management/instance-manager.ts

@@ -65,6 +65,7 @@ class InstanceManager {
           return;
         }
 
+        this.sharedManager.detachSharedDirectories(instancePath);
         this.sharedManager.normalizeSharedPluginMetadataPaths();
       });
     });