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

@@ -96,8 +96,8 @@
       "repo": "https://github.com/hugohe3/ppt-master.git",
       "ref": "main",
       "adapter": "claude-skill",
-      "commit": "eb095bfcc6b625fd8754e9f5d053ec4220865370",
-      "syncedAt": "2026-08-08T16:00:01Z"
+      "commit": "108b4b82db1b6076284bd68f603422044899eaf2",
+      "syncedAt": "2026-08-09T16:00:00Z"
     },
     {
       "id": "next-skills",
@@ -105,8 +105,8 @@
       "repo": "https://github.com/vercel/next.js.git",
       "ref": "canary",
       "adapter": "skill-collection",
-      "commit": "a677cf66af002fbdcf49a982ef435b03554817cc",
-      "syncedAt": "2026-08-08T16:00:01Z"
+      "commit": "62d9b8e03160727191bdcecd96c2284575621501",
+      "syncedAt": "2026-08-09T16:00:00Z"
     }
   ]
 }