chore: bump version to v2.2.0 and update documentation

Version updates:
- marketplace.json metadata.version: 2.0.0 → 2.2.0
- marketplace.json projman version: 2.0.0 → 2.2.0
- plugins/projman/plugin.json version: 2.0.0 → 2.2.0

Documentation updates:
- CHANGELOG.md: Changed [Unreleased] to [2.2.0] - 2026-01-20
- README.md: Updated projman version to v2.2.0
- README.md: Added /review and /test-check to commands list
- README.md: Added code-reviewer to agent list
- README.md: Updated Key Features section to v2.2.0
- README.md: Added validate-marketplace.sh to structure
- plugins/projman/README.md: Updated title to v2.2.0
- plugins/projman/README.md: Updated version changelog

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.claude-plugin/marketplace.json

@@ -6,12 +6,12 @@
   },
   "metadata": {
     "description": "Project management plugins with Gitea and NetBox integrations",
-    "version": "2.0.0"
+    "version": "2.2.0"
   },
   "plugins": [
     {
       "name": "projman",
-      "version": "2.0.0",
+      "version": "2.2.0",
       "description": "Sprint planning and project management with Gitea integration",
       "source": "./plugins/projman",
       "author": {