scp's own user@host:path parser splits on the space in 'speaker ready'
even when the shell argument is quoted. ssh already handles it correctly.
Upload: ssh cat < file; Download: ssh cat > file.
Copies display_control.m to laptop 01 via SSH, compiles universal binary
(x86_64 + arm64) on the remote Mac, pulls binary back to resources/bin/.
Defaults to 192.168.32.101; accepts optional IP override as $1.
README: restructure display_control build section — Option A (remote from
workstation, preferred) and Option B (direct on Mac).