Fix plugin.json structure to match Claude Code spec

- Changed agents and commands to path strings (not objects)
- Removed non-spec components field
- Updated marketplace.json description (removed hooks reference)

This fixes agent and command discovery issues.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

.claude-plugin/marketplace.json

@@ -11,7 +11,7 @@
   "plugins": [
     {
       "name": "compounding-engineering",
-      "description": "AI-powered development tools that get smarter with every use. Make each unit of engineering work easier than the last. Includes 15 specialized agents, 6 commands, and automated hooks.",
+      "description": "AI-powered development tools that get smarter with every use. Make each unit of engineering work easier than the last. Includes 15 specialized agents and 6 commands.",
       "version": "1.0.0",
       "author": {
         "name": "Kieran Klaassen",