Add code-review plugin to marketplace.json

Added marketplace entry for the code-review plugin, which provides automated PR review using multiple specialized agents with confidence-based scoring.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

.claude-plugin/marketplace.json

@@ -57,6 +57,17 @@
       },
       "source": "./plugins/security-guidance",
       "category": "security"
+    },
+    {
+      "name": "code-review",
+      "description": "Automated code review for pull requests using multiple specialized agents with confidence-based scoring to filter false positives",
+      "version": "1.0.0",
+      "author": {
+        "name": "Boris Cherny",
+        "email": "boris@anthropic.com"
+      },
+      "source": "./plugins/code-review",
+      "category": "productivity"
     }
   ]
 }