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

@@ -33,8 +33,8 @@
       "repo": "https://github.com/shadcn-ui/ui.git",
       "ref": "main",
       "adapter": "claude-skill",
-      "commit": "a72491cb9b5f9471392fdc179bbb61739e37ec72",
-      "syncedAt": "2026-06-27T16:00:00Z"
+      "commit": "af79276f7e43ccb40059f7db67f9ff42afa0e174",
+      "syncedAt": "2026-06-29T15:59:59Z"
     },
     {
       "id": "frontend-slides",
@@ -69,8 +69,8 @@
       "repo": "https://github.com/hugohe3/ppt-master.git",
       "ref": "main",
       "adapter": "claude-skill",
-      "commit": "8e2b5b9a0312df3710568d8a0638d1b53356af2b",
-      "syncedAt": "2026-06-28T16:00:00Z"
+      "commit": "f888bff138f96e9e5e2e43f8c90c66695e979f60",
+      "syncedAt": "2026-06-29T15:59:59Z"
     },
     {
       "id": "next-skills",
@@ -78,8 +78,8 @@
       "repo": "https://github.com/vercel/next.js.git",
       "ref": "canary",
       "adapter": "skill-collection",
-      "commit": "f509282984a400b3316265c24e585873c97b8309",
-      "syncedAt": "2026-06-28T16:00:00Z"
+      "commit": "1682685a357bb219a07499f1f846603d430ef796",
+      "syncedAt": "2026-06-29T15:59:59Z"
     }
   ]
 }