feat: Support customized system prompt base

[quqixun]

Pre-submission checklist

• I have searched existing issues and this feature hasn't been requested before | 我已搜索现有问题，确认此功能尚未被请求
• I have read the project documentation and confirmed this feature doesn't already exist | 我已阅读项目文档并确认此功能尚未存在
• This feature request is specific to MemOS and not a general software issue | 该功能请求是针对 MemOS 的，而不是一般软件问题

Problem Statement

There is an uneditable base_prmopt in _build_system_prompt .

Please support customized system prompt base.

Implementation Contribution

• I'm willing to implement this feature myself | 我愿意自己实现此功能
• I would like someone else to implement this | 我希望其他人来实现此功能

[newmeta-ben]

I've just hit this problem as well, I can probably implement - seems relatively straight forward.

Is there a preferred design choice here where/how the base prompt should be made available?

i.e
mos.set_base_prompt(base_prompt=)
mos.chat(query=, user_id=, base_prompt=)

[fridayL]

I've just hit this problem as well, I can probably implement - seems relatively straight forward.

Is there a preferred design choice here where/how the base prompt should be made available?

i.e mos.set_base_prompt(base_prompt=) mos.chat(query=, user_id=, base_prompt=)

I think this is a great suggestion. If possible, you could submit a PR to write this logic.

[newmeta-ben]

@fridayL - PR has been created.
#102