Feature: Multi-repository mode

[mtojek]

In my workflow, I often need to introduce changes in one repository while simultaneously referencing interfaces, types, or contracts defined in another repository.

Currently, Mux can operate only within a single repository context. When it needs to reference another repository, it falls back to fetching files via the GitHub API (e.g. using curl). This approach is slow, inefficient, and breaks the flow, especially for larger repositories or frequent cross-repo lookups.

[ibetitsmike]

You can already tell the Mux agent to look at a different repo. Another approach can also be to tell the agent to clone the other repo to a temporary folder.

In ~/.mux/AGENTS.md you can just have a line "If you want to look at a different repo just clone it".

We're thinking of having a different more sustainable approach, but as a workaround this should be better.