fix(plugin): separate client marketplace registrations (#908)

Register the Claude Code and Codex integrations in their respective native marketplace manifests so each client only exposes its compatible plugin.

Co-authored-by: Xwell <180168103+Xvvln@users.noreply.github.com>

.agents/plugins/marketplace.json

@@ -0,0 +1,20 @@
+{
+  "name": "open-code-review",
+  "interface": {
+    "displayName": "Open Code Review"
+  },
+  "plugins": [
+    {
+      "name": "open-code-review-codex",
+      "source": {
+        "source": "local",
+        "path": "./plugins/open-code-review"
+      },
+      "policy": {
+        "installation": "AVAILABLE",
+        "authentication": "ON_INSTALL"
+      },
+      "category": "Developer Tools"
+    }
+  ]
+}

.claude-plugin/marketplace.json

@@ -11,10 +11,6 @@
       "description": "Perform AI code review on Git diffs — supports workspace changes, branch ranges, and single commits with concurrent per-file analysis, codebase search, and deep context-aware review.",
       "version": "1.0.0",
       "license": "Apache-2.0"
-    },
-    {
-      "name": "open-code-review-codex",
-      "source": "./plugins/open-code-review"
     }
   ]
 }