Add V-Model Extension Pack to catalog

First community extension: V-Model paired dev-spec and test-spec
generation with regulatory-grade traceability.

- 3 commands: requirements, acceptance, trace
- Deterministic coverage validation (regex-based, not AI)
- Targets: IEC 62304, ISO 26262, DO-178C, FDA 21 CFR Part 820
- Repository: https://github.com/leocamello/spec-kit-v-model
- Release: v0.1.0

Author: leocamello

extensions/catalog.json

@@ -1,6 +1,35 @@
 {
   "schema_version": "1.0",
-  "updated_at": "2026-02-03T00:00:00Z",
+  "updated_at": "2026-02-20T00:00:00Z",
   "catalog_url": "https://raw.githubusercontent.com/github/spec-kit/main/extensions/catalog.json",
-  "extensions": {}
+  "extensions": {
+    "v-model": {
+      "name": "V-Model Extension Pack",
+      "id": "v-model",
+      "description": "Enforces V-Model paired generation of development specs and test specs with full traceability.",
+      "author": "leocamello",
+      "version": "0.1.0",
+      "download_url": "https://github.com/leocamello/spec-kit-v-model/archive/refs/tags/v0.1.0.zip",
+      "repository": "https://github.com/leocamello/spec-kit-v-model",
+      "license": "MIT",
+      "requires": {
+        "speckit_version": ">=0.1.0"
+      },
+      "provides": {
+        "commands": [
+          "speckit.v-model.requirements",
+          "speckit.v-model.acceptance",
+          "speckit.v-model.trace"
+        ]
+      },
+      "tags": [
+        "v-model",
+        "traceability",
+        "testing",
+        "compliance",
+        "safety-critical"
+      ],
+      "verified": false
+    }
+  }
 }