Support dynamic skills and subagents for multi tenants

[Tony Wang (qweasd1)]

Hi,
thanks for creating this great project! I have a proposal want to share here and wish to hear feedback!

So my company is building a general agent running on the cloyd that allow customers to extend it with custom skills + custom agent. Since this is running on the cloud, different customer might want to enable different custom skills + agents. It's a little bit challenge to implement it with today's deepagents since the tools and subagents is defined globally in a fixed way. It would be nice the the skills and subagents can be dynamically filtered by the the thread config (e.g. filter by tenant id)

To implement this, I think we have several options:

1. we can add a custom filter function on the skill and subagent middleware and allow to pass in function that has thread config as input that return skills on skills and a similar function to return subagents on subagents, these functions can be pass through to the corresponding middlewares
2. we can allow people to override the default middleware as discussed here Overriding / Disable Default Deep Agents Middleware, Example + Community Thoughts #655, so people can custom the middlewares to add the filter.

I think this will be a pretty common feature for SaaS company when they try to build their agent. Feel free to share your thoughts on this! I'm happy to discuss and work on PR to get this work