Post metadata editor, 'view drafts' buttons not visible on mobile

[spiffytech]

Describe the bug

At breakpoints below 650px, when editing a post, the menu options for editing the post metadata or returning to the drafts view are not visible. Inability to edit metadata means posts can't be scheduled from a phone, and without the 'drafts' button, there is no UI to leave the editor without publishing the post.

Expected behavior

On mobile, I would expect all post content controls to be available, as well as high-level app navigation. I think these two are the most important ones missing, though dark mode would be good to have, too.

Since most of the left-hand nav vanishes at this same breakpoint, there seems to be room to display more of the right-hand nav.

Application configuration

• Single mode or Multi-user mode?: Single
• Database?: SQLite
• Open registration?: no
• Federation enabled?: no

Version or last commit: 0.13.1