Feature: Add ACP support via command-code acp for OpenClaw/acpx and other ACP clients

Feature Description

It would be great if Command Code exposed an ACP-compatible entrypoint, for example:

command-code acp

Fallback

Even a minimal ACP adapter around existing Command Code sessions would be useful. command-code -p works for one-shot tasks, but it does not provide proper ACP session lifecycle or streaming/tool semantics.

Use Case

OpenClaw supports external coding agents through ACPX, and can already run harnesses like Claude Code, Codex, Gemini, OpenCode, Kimi, etc. Command Code looks like a strong fit for this because it already has:

a CLI
non-interactive mode with command-code -p
model selection
permission modes
MCP support
taste/memory/session concepts

Then it could be registered as an external ACP harness from OpenClaw/acpx, e.g.:

{
  "agents": {
    "commandcode": {
      "command": "command-code acp"
    }
  }
}

Additional Context

No response

從現有的非互動式進入點 command-code -p 和提議的命令 command-code acp 開始。檢視目前的工作階段、模型選擇、權限模式、MCP 支援，以及串流或工具行為是如何提供的。當相容於 ACP 的進入點支援 OpenClaw/acpx 用戶端所需的工作階段生命週期和串流／工具語意時，即表示完成。