Update Multi-Model Review extension to v0.1.2 (#3066)

Update multi-model-review extension submitted by @formin to:
- extensions/catalog.community.json (version, download_url, updated_at)
- docs/community/extensions.md community extensions table

Closes #3065

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

extensions/catalog.community.json

@@ -1,6 +1,6 @@
 {
   "schema_version": "1.0",
-  "updated_at": "2026-06-17T00:00:00Z",
+  "updated_at": "2026-06-18T00:00:00Z",
   "catalog_url": "https://raw.githubusercontent.com/github/spec-kit/main/extensions/catalog.community.json",
   "extensions": {
     "aide": {
@@ -2063,8 +2063,8 @@
       "id": "multi-model-review",
       "description": "Cross-model Spec Kit handoffs for spec authoring, implementation routing, and review.",
       "author": "formin",
-      "version": "0.1.1",
-      "download_url": "https://github.com/formin/multi-model-review/archive/refs/tags/v0.1.1.zip",
+      "version": "0.1.2",
+      "download_url": "https://github.com/formin/multi-model-review/archive/refs/tags/v0.1.2.zip",
       "repository": "https://github.com/formin/multi-model-review",
       "homepage": "https://github.com/formin/multi-model-review",
       "documentation": "https://github.com/formin/multi-model-review/blob/main/README.md",
@@ -2108,7 +2108,7 @@
       "downloads": 0,
       "stars": 0,
       "created_at": "2026-05-04T02:51:52Z",
-      "updated_at": "2026-06-09T00:00:00Z"
+      "updated_at": "2026-06-18T00:00:00Z"
     },
     "multi-sites": {
       "name": "Multi-Sites Spec Kit",