Allow admins to set default teammate preferences at company level Merged

Problem
Admins cannot define default preference values for new or existing teammates. Certain default settings (such as single-key keyboard shortcuts) can cause usability issues, and admins have no way to change the baseline.

Request
Allow admins to set default values for teammate preferences at the company or workspace level. Teammates should still be able to override these defaults individually if desired.

Context
For example, the default keyboard shortcut mode includes single-key shortcuts, which can cause accidental actions like mass-deleting emails. Admins want to set safer defaults while letting power users opt in.