Feature Request: enabled option to switch enable/disable MCP servers

[pokutuna]

Thank you for creating this great tool. I'm using mcp-proxy to consolidate multiple MCP sedskrver configurations for multiple local AI tools.

I'd like to propose adding an enabled boolean field to the per-server options. This would allow temporarily disabling servers while preserving their configuration.

I use this tool as a centralized place to manage connection configurations for many MCP servers. Since JSON doesn't support comments, being able to temporarily disable servers without removing their config would be very helpful for testing and switching between different server sets

Like this:

{
  "mcpServers": {
    "github": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-github"],
      "env": { "GITHUB_TOKEN": "${GITHUB_TOKEN}" }
      // enabled: true (default)
    },
    "experimental-server": {
      "command": "npx",
      "args": ["-y", "some-experimental-mcp-server"],
      "options": {
        "enabled": false  // temporarily disabled, but config preserved
      }
    }
  }
}

Setting the default to enabled: true (when omitted) would maintain backward compatibility with existing configurations.
The implementation would be simple, just skip client initialization when enabled: false.

[TBXark]

The default value of true isn't quite appropriate, so I've changed the field name to Disabled.