fix(management): localize marketplace registry per instance

src/management/instance-manager.ts

@@ -26,11 +26,13 @@ class InstanceManager {
   private readonly instancesDir: string;
   private readonly sharedManager: SharedManager;
   private readonly contextSyncLock: ProfileContextSyncLock;
+  private readonly pluginLayoutLock: ProfileContextSyncLock;
 
   constructor() {
     this.instancesDir = path.join(getCcsDir(), 'instances');
     this.sharedManager = new SharedManager();
     this.contextSyncLock = new ProfileContextSyncLock(this.instancesDir);
+    this.pluginLayoutLock = new ProfileContextSyncLock(this.instancesDir);
   }
 
   /**
@@ -56,9 +58,15 @@ class InstanceManager {
       // Apply context policy (isolated by default, optional shared group).
       await this.sharedManager.syncProjectContext(instancePath, contextPolicy);
       await this.sharedManager.syncAdvancedContinuityArtifacts(instancePath, contextPolicy);
+
+      if (!options.bare) {
+        await this.pluginLayoutLock.withNamedLock('__plugin-layout__', async () => {
+          this.sharedManager.linkSharedDirectories(instancePath);
+        });
+      }
     });
 
-    this.sharedManager.normalizeSharedPluginMetadataPaths(instancePath);
+    this.sharedManager.normalizeSharedPluginMetadataPaths(options.bare ? undefined : instancePath);
 
     // Sync MCP servers from global ~/.claude.json (unless bare)
     if (!options.bare) {
@@ -82,7 +90,7 @@ class InstanceManager {
   private initializeInstance(
     profileName: string,
     instancePath: string,
-    options: InstanceOptions = {}
+    _options: InstanceOptions = {}
   ): void {
     try {
       // Create base directory
@@ -106,10 +114,7 @@ class InstanceManager {
         }
       });
 
-      // Bare profiles skip shared symlinks (commands, skills, agents, settings.json)
-      if (!options.bare) {
-        this.sharedManager.linkSharedDirectories(instancePath);
-      }
+      // Shared links are created during ensureInstance() under the plugin layout lock.
     } catch (error) {
       throw new Error(
         `Failed to initialize instance for ${profileName}: ${(error as Error).message}`