ComfyUI unified gateway

• /mcp → combined MCP server (krea-minimax + hunyuan3d tools, one endpoint)
• /krea/mcp → krea-minimax MCP server only (127.0.0.1:8000)
• /hunyuan/mcp → hunyuan3d MCP server only (127.0.0.1:8002)
• /comfy/ → ComfyUI itself (127.0.0.1:8001)