Adds a new HID_CMD_BATTERY (0x44) command to the shared qmk-host protocol.
When the keyboard is in wireless transport mode (BT or 2.4G) the firmware
now pushes the current battery percentage to the host:
- Periodic push every 5 minutes via timer_read32()/timer_elapsed32(); fires
immediately on the first matrix_scan_user() call after boot so qmk-host
gets a reading as soon as the keyboard connects over USB in wireless mode.
- Redundant sends are suppressed: g_last_sent_bat tracks the last value
transmitted and the packet is skipped when the level has not changed.
- Query-response path: qmk-host can send CMD_BATTERY with HID_FLAG_QUERY at
any time; the keyboard replies with the current percentage or
HID_BATT_UNAVAILABLE (0xFF) when in USB transport mode.
- All battery and transport code is guarded by #ifdef LK_WIRELESS_ENABLE so
the keymap compiles cleanly on any wired-only build.
Firmware size delta: +160 bytes (well within flash budget).
rootiest
0fa528b3dd
