Unprototype Drydock

Summary:
Ref T10246. Drydock still has a few outstanding issues, but it's mostly minor UI stuff and the documentation has reasonable caveats about it.

Broadly, I don't expect to make any major changes to Drydock in the future (i.e., all the fundamentals seem sound at this point) and it doesn't have any major technical debt or, like, obsolete APIs or anything.

Test Plan: Saw "Drydock" as not-a-prototype in Applications.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T10246

Differential Revision: https://secure.phabricator.com/D15401