Add hid_protocol.h defining a shared 32-byte packet structure for the
qmk-host bridge application (command IDs 0x40-0x7E, clear of VIA's
range). Implement via_command_kb() in keymap.c to intercept incoming
packets: LAYER_SYNC applies a new active layer, VOLUME and BRIGHTNESS
store host-reported values for future RGB indicators, and ACTIVE_APP
is stubbed for a later commit. Layer state changes are broadcast to the
host via raw_hid_send() from layer_state_set_user(), guarded by
g_hid_recv_active to prevent echo loops when the change itself
originated from HID.
rootiest
6fd5179c55
