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

@@ -6,8 +6,8 @@
       "repo": "https://github.com/anthropics/skills.git",
       "ref": "main",
       "adapter": "claude-skill",
-      "commit": "9d630808e4add0a7146de4af9384155d5dee350a",
-      "syncedAt": "2026-10-09T10:26:29Z"
+      "commit": "dbd4588f9e1033efb41dad4bef2f7947c8993d44",
+      "syncedAt": "2026-10-10T16:00:00Z"
     },
     {
       "id": "pdf",
@@ -15,8 +15,8 @@
       "repo": "https://github.com/anthropics/skills.git",
       "ref": "main",
       "adapter": "claude-skill",
-      "commit": "9d630808e4add0a7146de4af9384155d5dee350a",
-      "syncedAt": "2026-10-09T10:26:29Z"
+      "commit": "dbd4588f9e1033efb41dad4bef2f7947c8993d44",
+      "syncedAt": "2026-10-10T16:00:00Z"
     },
     {
       "id": "pptx",
@@ -24,8 +24,8 @@
       "repo": "https://github.com/anthropics/skills.git",
       "ref": "main",
       "adapter": "claude-skill",
-      "commit": "9d630808e4add0a7146de4af9384155d5dee350a",
-      "syncedAt": "2026-10-09T10:26:29Z"
+      "commit": "dbd4588f9e1033efb41dad4bef2f7947c8993d44",
+      "syncedAt": "2026-10-10T16:00:00Z"
     },
     {
       "id": "xlsx",
@@ -33,8 +33,8 @@
       "repo": "https://github.com/anthropics/skills.git",
       "ref": "main",
       "adapter": "claude-skill",
-      "commit": "9d630808e4add0a7146de4af9384155d5dee350a",
-      "syncedAt": "2026-10-09T10:26:29Z"
+      "commit": "dbd4588f9e1033efb41dad4bef2f7947c8993d44",
+      "syncedAt": "2026-10-10T16:00:00Z"
     },
     {
       "id": "find-skills",
@@ -42,8 +42,8 @@
       "repo": "https://github.com/vercel-labs/skills.git",
       "ref": "main",
       "adapter": "claude-skill",
-      "commit": "e878c4502674f84094dc27b5ad94ddaf64f22551",
-      "syncedAt": "2026-10-09T10:26:29Z"
+      "commit": "13e4063a1cf913f5606d57d42ab83a86f5001e04",
+      "syncedAt": "2026-10-10T16:00:00Z"
     },
     {
       "id": "generate-agents-md",
@@ -123,8 +123,8 @@
       "repo": "https://github.com/Leonxlnx/taste-skill.git",
       "ref": "main",
       "adapter": "skill-collection",
-      "commit": "18dfc928b135629e0eddfdd445a06400d04ed439",
-      "syncedAt": "2026-10-09T02:04:00Z"
+      "commit": "717446e07a78d4e6d7918b1fde1a263378eebac9",
+      "syncedAt": "2026-10-10T16:00:00Z"
     },
     {
       "id": "shadcn",
@@ -132,8 +132,8 @@
       "repo": "https://github.com/shadcn-ui/ui.git",
       "ref": "main",
       "adapter": "claude-skill",
-      "commit": "2d3f1cd436b18ea12f24130de4df781355925b08",
-      "syncedAt": "2026-10-09T16:00:00Z"
+      "commit": "c2a67849be260701852b0977ba15eb5f3a0ce2a4",
+      "syncedAt": "2026-10-10T16:00:00Z"
     },
     {
       "id": "frontend-slides",
@@ -258,8 +258,8 @@
       "repo": "https://github.com/vercel/next.js.git",
       "ref": "canary",
       "adapter": "skill-collection",
-      "commit": "2d0da21235fdf3554244bf4c5c19369fbcd6b37b",
-      "syncedAt": "2026-10-09T16:00:00Z"
+      "commit": "d8bfc3c994670c367e6e31853b78f42e8b7fba85",
+      "syncedAt": "2026-10-10T16:00:00Z"
     },
     {
       "id": "shuorenhua",