Add Product Spec Extension to community catalog (#2705)

Add product extension submitted by @d0whc3r to:
- extensions/catalog.community.json (alphabetical order)
- docs/community/extensions.md community extensions table

Closes #2700

docs/community/extensions.md

@@ -78,6 +78,7 @@ The following community-contributed extensions are available in [`catalog.commun
 | PR Bridge | Auto-generate pull request descriptions, checklists, and summaries from spec artifacts | `process` | Read-only | [spec-kit-pr-bridge-](https://github.com/Quratulain-bilal/spec-kit-pr-bridge-) |
 | Presetify | Create and validate presets and preset catalogs | `process` | Read+Write | [presetify](https://github.com/mnriem/spec-kit-extensions/tree/main/presetify) |
 | Product Forge | Full product lifecycle from research to release — portfolio, lite mode, monorepo, optional V-Model | `process` | Read+Write | [speckit-product-forge](https://github.com/VaiYav/speckit-product-forge) |
+| Product Spec Extension | Generates PRFAQ, Lean PRD, stakeholder summaries, and technical designs from engineering specs | `docs` | Read+Write | [spec-kit-product](https://github.com/d0whc3r/spec-kit-product) |
 | Project Health Check | Diagnose a Spec Kit project and report health issues across structure, agents, features, scripts, extensions, and git | `visibility` | Read-only | [spec-kit-doctor](https://github.com/KhawarHabibKhan/spec-kit-doctor) |
 | Project Status | Show current SDD workflow progress — active feature, artifact status, task completion, workflow phase, and extensions summary | `visibility` | Read-only | [spec-kit-status](https://github.com/KhawarHabibKhan/spec-kit-status) |
 | QA Testing Extension | Systematic QA testing with browser-driven or CLI-based validation of acceptance criteria from spec | `code` | Read-only | [spec-kit-qa](https://github.com/arunt14/spec-kit-qa) |

extensions/catalog.community.json

@@ -1,6 +1,6 @@
 {
   "schema_version": "1.0",
-  "updated_at": "2026-05-21T00:00:00Z",
+  "updated_at": "2026-05-26T00:00:00Z",
   "catalog_url": "https://raw.githubusercontent.com/github/spec-kit/main/extensions/catalog.community.json",
   "extensions": {
     "aide": {
@@ -1945,6 +1945,38 @@
       "created_at": "2026-05-15T00:00:00Z",
       "updated_at": "2026-05-15T00:00:00Z"
     },
+    "product": {
+      "name": "Product Spec Extension",
+      "id": "product",
+      "description": "Generates PRFAQ, Lean PRD, stakeholder summaries, and technical designs from engineering specs.",
+      "author": "spec-kit-product contributors",
+      "version": "0.1.3",
+      "download_url": "https://github.com/d0whc3r/spec-kit-product/releases/download/v0.1.3/product-0.1.3.zip",
+      "repository": "https://github.com/d0whc3r/spec-kit-product",
+      "homepage": "https://github.com/d0whc3r/spec-kit-product",
+      "documentation": "https://github.com/d0whc3r/spec-kit-product/blob/main/README.md",
+      "changelog": "https://github.com/d0whc3r/spec-kit-product/blob/main/CHANGELOG.md",
+      "license": "MIT",
+      "requires": {
+        "speckit_version": ">=0.2.0"
+      },
+      "provides": {
+        "commands": 4,
+        "hooks": 6
+      },
+      "tags": [
+        "product",
+        "spec",
+        "prd",
+        "design",
+        "documentation"
+      ],
+      "verified": false,
+      "downloads": 0,
+      "stars": 0,
+      "created_at": "2026-05-26T00:00:00Z",
+      "updated_at": "2026-05-26T00:00:00Z"
+    },
     "product-forge": {
       "name": "Product Forge",
       "id": "product-forge",