Muse Spark via OpenCode Go in DeepSeek Harness (DSH)

让 muse-spark-1.2-contributor（OpenCode Zen Go 网关）在 DeepSeek Harness（deepseek-harness / pi-ai）里正确工作：首轮出内容 + 多轮 thinking 回传不报错。

Make muse-spark-1.2-contributor (the OpenCode Zen Go gateway model) work correctly in DeepSeek Harness (deepseek-harness / pi-ai): first-turn output plus lossless multi-turn thinking replay.

免责声明 / Disclaimer：本仓库是个人技术分享，非 DeepSeek / opencode 官方项目，与 deepseek-ai、sst/opencode、opencode.ai 均无关联。文中涉及的协议与代码分析基于公开接口，仅用于学习与自用。
This is a personal tech-sharing repo. It is not an official DeepSeek or opencode project and is unrelated to deepseek-ai, sst/opencode, or opencode.ai. Protocol/code analysis herein is based on public interfaces, for learning and personal use only.

项目	值
模型	muse-spark-1.2-contributor (Muse Spark 1.2 Contributor)
网关	OpenCode Zen Go — https://opencode.ai/zen/go/v1
协议（正确）	OpenAI Responses API (openai-responses)
宿主	DeepSeek Harness (deepseek-harness), LLM 适配层 @deepseek-ai/dsh-llm-pi-ai → @earendil-works/pi-ai
状态	✅ 已验证：多轮 + thinking 回传 + 工具调用 + 图片输入 正常

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一、问题现象 / Symptoms

在 ~/.dsh/settings.yaml 里用 muse-spark-1.2-contributor，无论怎么配都会遇到下列错误之一：

配置的协议	现象
openai-completions	Stream ended without finish_reason（流被网关截断，message.content 恒为空）
anthropic-messages	model returned a completed response with no content（非流式空回复）
openai-responses + 错误的 assistant 补丁	input[5] did not match any supported type（发了 responses 不认识的输入项）
openai-responses（原始）多轮	reasoning_content in the thinking mode must be passed back to the API

而 在 opencode 官方客户端里，Muse 完全正常。

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二、为什么 opencode 能用 / Why it works in opencode

opencode 的模型目录来自 https://models.opencode.ai/api.json（本地缓存在 ~/.cache/opencode/models.json）。其中：

// provider "opencode-go"
{
  "id": "opencode-go",
  "npm": "@ai-sdk/openai-compatible",
  "api": "https://opencode.ai/zen/go/v1"
}
// model "muse-spark-1.2-contributor"
{
  "provider": { "npm": "@ai-sdk/openai" },   // ← 关键：模型级覆盖为 OpenAI Responses SDK
  "reasoning_options": [
    { "type": "effort", "values": ["minimal", "low", "medium", "high", "xhigh"] }
  ],
  "limit": { "context": 1048576, "output": 131072 }
}

Muse 只认 OpenAI Responses 协议（模型级 @ai-sdk/openai），不是 Chat Completions、也不是