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

@@ -24,8 +24,8 @@
       "repo": "https://github.com/nextlevelbuilder/ui-ux-pro-max-skill.git",
       "ref": "main",
       "adapter": "claude-skill",
-      "commit": "10d6ca310541d3ffeee6dceda0a29e373796f321",
-      "syncedAt": "2026-06-21T16:00:01Z"
+      "commit": "9a863a527534eeff97cad45430b8e5678ab45c40",
+      "syncedAt": "2026-06-22T16:00:01Z"
     },
     {
       "id": "shadcn",
@@ -69,8 +69,8 @@
       "repo": "https://github.com/hugohe3/ppt-master.git",
       "ref": "main",
       "adapter": "claude-skill",
-      "commit": "c0ace9d5d7cfa991d550ec4c54cf7722ffbcff07",
-      "syncedAt": "2026-06-21T16:00:01Z"
+      "commit": "bf9ae01a8df43b1a86f459ed007e84ef465ae257",
+      "syncedAt": "2026-06-22T16:00:01Z"
     },
     {
       "id": "next-skills",