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/nextlevelbuilder/ui-ux-pro-max-skill.git",
       "ref": "main",
       "adapter": "claude-skill",
-      "commit": "d8ce090f82580c68f5471cc6dd3f56faf9a37afb",
-      "syncedAt": "2026-09-15T06:47:43Z"
+      "commit": "7643fd1501eed926a83d106f92190d1a769c6796",
+      "syncedAt": "2026-09-15T09:16:34Z"
     },
     {
       "id": "caveman",
@@ -144,14 +144,41 @@
       "commit": "057d5e82410c789c0c8b16412c41c119d13cb192",
       "syncedAt": "2026-09-15T07:53:22Z"
     },
+    {
+      "id": "embedded-app-pc-debug",
+      "pluginName": "embedded-app-pc-debug",
+      "repo": "https://git.playones.com/zoukai/embedded-app-pc-debug.git",
+      "ref": "v1.0.0",
+      "adapter": "claude-skill",
+      "commit": "cfb586cb5ffc5a69e66cd9adbc57e4ebf725d1d3",
+      "syncedAt": "2026-09-15T09:16:34Z"
+    },
+    {
+      "id": "firmware-app-development",
+      "pluginName": "firmware-app-development",
+      "repo": "https://git.playones.com/zoukai/firmware-app-development.git",
+      "ref": "1.0.0",
+      "adapter": "claude-skill",
+      "commit": "982171299a86922eb0577376cac9449520c0de55",
+      "syncedAt": "2026-09-15T09:16:34Z"
+    },
+    {
+      "id": "firmware-lowlevel-development",
+      "pluginName": "firmware-lowlevel-development",
+      "repo": "https://git.playones.com/tangfahong/firmware-lowlevel-development.git",
+      "ref": "v1.0.0",
+      "adapter": "skill-collection",
+      "commit": "bcea35a91eb8cdd59de90ee79a8ffa0d80037668",
+      "syncedAt": "2026-09-15T09:16:34Z"
+    },
     {
       "id": "next-skills",
       "pluginName": "next-skills",
       "repo": "https://github.com/vercel/next.js.git",
       "ref": "canary",
       "adapter": "skill-collection",
-      "commit": "85e574a682254a835b9fbdb61530e555cd2d12c6",
-      "syncedAt": "2026-09-15T06:47:43Z"
+      "commit": "e29a96a9eea4821af9fecd2edbd73e45e513e80d",
+      "syncedAt": "2026-09-15T09:16:34Z"
     },
     {
       "id": "shuorenhua",