Add archify-vscode-ext skill: Archify diagrams and models for the Archify Diagram Viewer extension

Model tasks (validate, list, scaffold, resolve), diagram tasks (validate,
render), the bundled Archify 3.0.1 runtime and yaml parser under
scripts/vendor, references for authoring, formats and folders, and the
online-shop example model.

scripts/vendor/archify/skill-release.json

@@ -0,0 +1,10 @@
+{
+  "schemaVersion": 1,
+  "skillId": "archify",
+  "channel": "stable",
+  "version": "3.0.1",
+  "source": {
+    "repository": "https://github.com/tt-a1i/archify"
+  },
+  "updateManifestUrl": "https://tt-a1i.github.io/archify/skill-updates/archify/stable.json"
+}