This PR adjusts the default panel layout for anyone on the agent v2
feature flag.

Note that this changes the right status bar items to show in reverse
priority order, and then adjusts priorities so that the "project
management" buttons appear to the right, and the outline panel appears
to the far left. The reversal "cancels out" most of the priority
changes, except the outline panel and the collab panel.


## Self-Review Checklist

<!-- Check before requesting review: -->
- [x] I've reviewed my own diff for quality, security, and reliability
- [x] Unsafe blocks (if any) have justifying comments
- [x] The content is consistent with the [UI/UX
checklist](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)
- [x] Tests cover the new/changed behavior
- [x] Performance impact has been considered and is acceptable

Release Notes:

- Swapped the order of the collab and outline status bar buttons