Fix Docker image namespace for root MCP server (github#67)

Change image from rootpublic/mcp-proxy to mcp/root to comply with build system requirements that expect images in the mcp/ namespace.

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

Co-authored-by: Shaked Dembo <shaked.dembo@root.io>
Co-authored-by: Claude <noreply@anthropic.com>

Author: shakedembo

servers/root/server.yaml

@@ -1,5 +1,5 @@
 name: root
-image: rootpublic/mcp-proxy
+image: mcp/root
 type: server
 meta:
   category: security