Restrict MCP access to private repositories

### Describe the feature or problem you’d like to solve

Currently, I can not find a documented method, or a method within the issues/discussions to restrict a local MCP deployment to access only specific repositories (In my case, private repos belonging to the org). I also don't see this option when creating the PAT, as even the "Only select repositories" includes "Also includes public repositories (read-only)."
I have seen some suggestions of modifying the prompt to account for this, but that doesn't offer a deterministic way of restricting the search space for repositories.

### Proposed solution

Offer some flag to restrict repo's by org name, and even further by repo name if wanted.
This would allow for agent's to have a focused selection of code, without relying on the model to strictly follow the prompt.