chore: update DocGuard extension to v0.21.1

Author: github-actions[bot]

extensions/catalog.community.json

@@ -1,6 +1,6 @@
 {
   "schema_version": "1.0",
-  "updated_at": "2026-05-26T00:00:00Z",
+  "updated_at": "2026-05-26T16:15:48Z",
   "catalog_url": "https://raw.githubusercontent.com/github/spec-kit/main/extensions/catalog.community.json",
   "extensions": {
     "aide": {
@@ -850,8 +850,8 @@
       "id": "docguard",
       "description": "Canonical-Driven Development enforcement. Validates, scores, and traces project documentation with automated checks, AI-driven workflows, and spec-kit hooks. Zero NPM runtime dependencies.",
       "author": "raccioly",
-      "version": "0.9.11",
-      "download_url": "https://github.com/raccioly/docguard/releases/download/v0.9.11/spec-kit-docguard-v0.9.11.zip",
+      "version": "0.21.1",
+      "download_url": "https://github.com/raccioly/docguard/releases/download/v0.21.1/spec-kit-docguard-v0.21.1.zip",
       "repository": "https://github.com/raccioly/docguard",
       "homepage": "https://www.npmjs.com/package/docguard-cli",
       "documentation": "https://github.com/raccioly/docguard/blob/main/extensions/spec-kit-docguard/README.md",
@@ -885,7 +885,7 @@
       "downloads": 0,
       "stars": 0,
       "created_at": "2026-03-13T00:00:00Z",
-      "updated_at": "2026-03-18T18:53:31Z"
+      "updated_at": "2026-05-26T16:15:48Z"
     },
     "doctor": {
       "name": "Project Health Check",