兼容LLM上下文中有空消息

[MarkShawn2020]

[16:39:51.717] DEBUG (default/3511956): >> calling LLM(provider=moonshot, model=moonshot-v1-8k, api_key=sk-BZ2XZcueSFSkkOzYbbTGmkdCM70TrsT0BDgKxqGv9CVjX5lo):
+----------------------------+
[user]: "hi"
[user]: "system list-models"
[user]: "hi"
[user]: "system set-preference features.chatter.model=moonshot-v1-8k"
[user]: "hi"
[user]: "hi"
[user]: "hi"
[user]: "hi"
[user]: "hi"
[user]: "hi"
[user]: "hi"
[user]: "hi"
[user]: "hi"
[user]: "hi"
[assistant]: ""
[user]: "1"
[user]: "1"
[user]: "1"
[user]: "1"
[user]: "1"
+----------------------------+
[16:39:51.717] INFO (default/3511956): 🌈 task(cnt=1)
[16:39:51.717] INFO (default/3511956): ⏳ task(cnt=0)
[16:39:51.752] INFO (default/3511956): ✅ task (cnt=0)
[16:39:51.805] ERROR (default/3511956): 400 Invalid request: agent message content is empty

[MarkShawn2020]

已完成 in https://github.com/MarkShawn2020/codebase/blob/78da55e9c0edc9762262b97558af9db2d82bc8c3/packages-core/llm/utils/call-llm.ts#L24