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": "3b74643f4d910f496babd4e634b1ba7168816f14",
-      "syncedAt": "2026-09-02T16:00:01Z"
+      "commit": "367fdb7f0f8f8e7994b5aab632c7ce5014802b32",
+      "syncedAt": "2026-09-04T16:00:00Z"
     },
     {
       "id": "taste-skill",
@@ -60,8 +60,8 @@
       "repo": "https://github.com/shadcn-ui/ui.git",
       "ref": "main",
       "adapter": "claude-skill",
-      "commit": "71e50952fbb7eda2c992660d36cd58671a2edf42",
-      "syncedAt": "2026-09-03T02:28:39Z"
+      "commit": "7c9eaba1c0a6404c990c144a654792e3313c650d",
+      "syncedAt": "2026-09-04T16:00:00Z"
     },
     {
       "id": "frontend-slides",
@@ -96,8 +96,8 @@
       "repo": "https://github.com/hugohe3/ppt-master.git",
       "ref": "main",
       "adapter": "claude-skill",
-      "commit": "6a8e91e244c987e49fbc4744be3b6d235f4f1e77",
-      "syncedAt": "2026-09-03T09:20:38Z"
+      "commit": "8295ca1416ad17cf25ed17765024bc7ba411782c",
+      "syncedAt": "2026-09-04T16:00:00Z"
     },
     {
       "id": "grill-me",
@@ -105,8 +105,8 @@
       "repo": "https://github.com/mattpocock/skills.git",
       "ref": "main",
       "adapter": "skill-collection",
-      "commit": "6654f6b60cd9d5be8b54c6fafe44346dabeb3b76",
-      "syncedAt": "2026-08-24T16:00:00Z"
+      "commit": "3cca18b368ae95cdbdebbff572ccafa662551015",
+      "syncedAt": "2026-09-04T16:00:00Z"
     },
     {
       "id": "updating-gitea-repositories",
@@ -123,8 +123,8 @@
       "repo": "https://git.playones.com/chenmingxuan/EP-Hub-Skill.git",
       "ref": "main",
       "adapter": "claude-skill",
-      "commit": "76cb0846d42e24bec29fbb3e3a39ea7f4338424e",
-      "syncedAt": "2026-09-03T02:28:39Z"
+      "commit": "5f9951aa6e249f86ebc84b1a12ba8e9e94ba3786",
+      "syncedAt": "2026-09-04T16:00:00Z"
     },
     {
       "id": "next-skills",
@@ -132,8 +132,8 @@
       "repo": "https://github.com/vercel/next.js.git",
       "ref": "canary",
       "adapter": "skill-collection",
-      "commit": "4e2abec31d4dd8df6040136e6f680c611418236f",
-      "syncedAt": "2026-09-03T16:00:00Z"
+      "commit": "602a2aba900e45fb2edd694f463f435430678e1f",
+      "syncedAt": "2026-09-04T16:00:00Z"
     },
     {
       "id": "shuorenhua",