chore: release v5.9.0

- Plugin installation scripts for consumer projects
- MCP server mapping via mcp_servers field in plugin.json
- CLAUDE.md section markers for install/uninstall
- Agent model selection (25 agents with model frontmatter)
- Agent frontmatter standardization

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

.claude-plugin/marketplace.json

@@ -6,7 +6,7 @@
   },
   "metadata": {
     "description": "Project management plugins with Gitea and NetBox integrations",
-    "version": "5.8.0"
+    "version": "5.9.0"
   },
   "plugins": [
     {