Restore the original screen order (keyboard first, then disk) and make Ctrl+C
on the keyboard screen the entry into OEM mode — the same hidden-Ctrl+C idiom
the disk-overwrite screen already uses for unencrypted installs. A confirm
guards against an accidental Ctrl+C; once confirmed, OEM jumps straight to
disk selection and the overwrite confirmation (no keyboard, no user), since
OEM is always a full-disk install. The 'OEM install' entry leaves the mode
picker. The harness drives the new path.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
