Sync third-party and MCP 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 and preserve normal incremental market Git history.
Tested: Marketplace validation passed.

config/external-sources.lock.json

@@ -42,8 +42,8 @@
       "repo": "https://github.com/JuliusBrussee/caveman.git",
       "ref": "main",
       "adapter": "codex-plugin",
-      "commit": "2f49f0e1a352aa810e70056b7930aeb0b3d219b4",
-      "syncedAt": "2026-08-21T06:41:32Z"
+      "commit": "7bb71309e8749a4f112aacd3a54b3941d8689905",
+      "syncedAt": "2026-08-23T16:00:00Z"
     },
     {
       "id": "taste-skill",
@@ -60,8 +60,8 @@
       "repo": "https://github.com/shadcn-ui/ui.git",
       "ref": "main",
       "adapter": "claude-skill",
-      "commit": "1773ecfeeb4a04366978d353e69b5c7ded78dcb2",
-      "syncedAt": "2026-08-22T16:00:00Z"
+      "commit": "ac60ef5c4db4265d71454dd9ecd3f93e255d7211",
+      "syncedAt": "2026-08-23T16:00:00Z"
     },
     {
       "id": "frontend-slides",
@@ -114,8 +114,8 @@
       "repo": "https://github.com/vercel/next.js.git",
       "ref": "canary",
       "adapter": "skill-collection",
-      "commit": "d898c8f590819fb54cdfa374c9181ade59eb7533",
-      "syncedAt": "2026-08-22T16:00:00Z"
+      "commit": "cb463843e78506c6b79518af8125af05e6cbac77",
+      "syncedAt": "2026-08-23T16:00:00Z"
     }
   ]
 }