chore: fix metadata gaps and add root CLAUDE.md

- llm-security SECURITY.md: update supported versions 3.0.x → 5.1.x
- config-audit plugin.json: add license, repository, keywords
- Add root CLAUDE.md with repo structure and conventions

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

plugins/config-audit/.claude-plugin/plugin.json

@@ -4,5 +4,8 @@
   "version": "3.0.1",
   "author": {
     "name": "Kjell Tore Guttormsen"
-  }
+  },
+  "license": "MIT",
+  "repository": "https://git.fromaitochitta.com/open/ktg-plugin-marketplace",
+  "keywords": ["configuration", "audit", "optimization", "health-check", "scanner"]
 }

plugins/llm-security/SECURITY.md

@@ -4,8 +4,8 @@
 
 | Version | Supported |
 |---------|-----------|
-| 3.0.x   | Yes       |
-| < 3.0   | No        |
+| 5.1.x   | Yes       |
+| < 5.0   | No        |
 
 ## Reporting a Vulnerability