Changes are not appearing until after a PR is created

### Short summary

Whenever changes are completed you are unable to view the changes unless you create a PR first

### Affected version or release

v0.2.12

### Installation context

_No response_

### What happened?

At a glance, this appears to be because it is assuming that the `master` branch is the correct branch for the diff. But this repository uses `main`, not `master`. It's failing on `git ["rev-parse", "master"]`. This was working until an update in the last few days.

Once a PR is created, the changes appear.

### Steps to reproduce

1. Create a session on a repository using `main` as the default branch
2. Let the session make changes
3. Attempt to view the changes.

### Expected behavior

Changes should be displayed

### Additional context

_No response_