feat: pass default_headers to get_openai_config() and pass extra_body to openai.OpenAI.embeddings.create()

[Insaniauser]

Pre-submission checklist | 提交前检查

• I have searched existing issues and this hasn't been mentioned before | 我已搜索现有问题，确认此问题尚未被提及
• I have read the project documentation and confirmed this issue doesn't already exist | 我已阅读项目文档并确认此问题尚未存在
• This issue is specific to MemOS and not a general software issue | 该问题是针对 MemOS 的，而不是一般软件问题

Problem Statement | 问题陈述

MemOS/src/memos/api/config.py

Line 264 in 6a43b49

def get_openai_config() -> dict[str, Any]:

自定义的大模型API接口要求传入应用鉴权信息，需要允许get_openai_config传递default_headers参数

MemOS/src/memos/embedders/universal_api.py

Line 81 in 6a43b49

return self.client.embeddings.create(

使用的jina-embeddings-v4模型要求传入extra_body={"task": "retrieval"}，需要允许openai.OpenAI.embeddings.create传递extra_body参数

Willingness to Implement | 实现意愿

• I'm willing to implement this myself | 我愿意自己解决
• I would like someone else to implement this | 我希望其他人来解决

[hijzy]

Added to the iteration plan. It will be implemented in a future release. Thanks for the suggestion and feedback.

已加入迭代计划，将在后续版本中进行实现。感谢你的建议与反馈。