Top bar scrolls out of view when mobile keyboard opens

[aethernet]

Problem

On mobile, the top bar (header/navigation) is normally pinned and visible. However, when the on-screen keyboard opens (e.g. when focusing an input field to type a message), the top bar gets pushed out of view.

This means the user loses access to navigation and controls while typing, which is precisely when they're actively interacting with the app.

Expected behavior

The top bar should remain pinned to the top of the viewport even when the on-screen keyboard opens, so navigation and controls stay accessible while typing.

Context

• This is specifically a mobile issue triggered by the keyboard appearing.
• Likely related to how the viewport/layout responds to the keyboard (e.g. visual viewport API, position: sticky vs fixed, or lack of handling for resize/visualViewport events).
• Also related to Workspace view is not responsive: gadget panel clipped, chat squeezed on phones #64 (general mobile responsiveness of the workspace view).