Sync third-party marketplace plugins

Constraint: Public skills are published only by explicit administrator action unless they are tracked third-party market sources.
Confidence: high
Scope-risk: narrow
Directive: Keep private/internal skills out of the public marketplace.
Tested: Marketplace validation passed.

plugins/codex/plugins/superpowers/.codex-plugin/plugin.json

@@ -42,8 +42,6 @@
     "brandColor": "#F59E0B",
     "composerIcon": "./assets/superpowers-small.svg",
     "logo": "./assets/app-icon.png",
-                      "screenshots":  [
+    "screenshots": []
-
-                                      ]
   }
 }

plugins/codex/plugins/ui-ux-pro-max/.codex-plugin/plugin.json

@@ -37,8 +37,6 @@
     "privacyPolicyURL": "https://github.com/nextlevelbuilder/ui-ux-pro-max-skill",
     "termsOfServiceURL": "https://github.com/nextlevelbuilder/ui-ux-pro-max-skill",
     "brandColor": "#7C3AED",
-                      "screenshots":  [
+    "screenshots": []
-
-                                      ]
   }
 }