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": "c72984e4392c7a154e55c11dbf445f01ce5c35d4",
-      "syncedAt": "2026-08-13T15:59:59Z"
+      "commit": "12aa8cc0e980b6d3310a5be4f477c434da51f4b0",
+      "syncedAt": "2026-08-15T16:00:01Z"
     },
     {
       "id": "taste-skill",
@@ -96,8 +96,8 @@
       "repo": "https://github.com/hugohe3/ppt-master.git",
       "ref": "main",
       "adapter": "claude-skill",
-      "commit": "b87f5f524cabff9376355163c0f2c622ead43493",
-      "syncedAt": "2026-08-14T16:00:00Z"
+      "commit": "090a133040d9bf41dca887dab78386c553af5dc6",
+      "syncedAt": "2026-08-15T16:00:01Z"
     },
     {
       "id": "grill-me",
@@ -114,8 +114,8 @@
       "repo": "https://github.com/vercel/next.js.git",
       "ref": "canary",
       "adapter": "skill-collection",
-      "commit": "a02b83fd53a66548520a5dff4ac61a0e18b83733",
-      "syncedAt": "2026-08-14T16:00:00Z"
+      "commit": "6d0379d4b8558d1157dee78906f0850432453a21",
+      "syncedAt": "2026-08-15T16:00:01Z"
     }
   ]
 }