R1:5295c6ba1e61

Use EditEngine for Harbormaster Build Plans, fix some crumbs/mobile stuff

Summary:
Ref T10457.

- Use EditEngine for Build Plans.
- Fix some minor issues with crumbs being inconsistent.
- Fix some minor issues with mobile menus not being consistent/available.

Test Plan:
- Created and edited build plans.
- Poked around in mobile width, verified mobile menu had the right stuff in it.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T10457

Differential Revision: https://secure.phabricator.