Add a whole-house <hdmi-matrix> section: NHAV-1632 device, the
hdmi_matrix integration's entity set (16 source selects enabled, 16
stream switches + 16 signal sensors disabled-by-default) and
send_command service, deploy steps (and the custom_components-subdir
backup trap), and the rear-panel LED semantics plus the suspect-dead
port-1 transmitter. Protocol depth points to the repo's docs/device-api.md.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
dev