Fixes and improvements (#616)

Tactility/Include/Tactility/lvgl/KeyboardDeviceListener.h

@@ -0,0 +1,21 @@
+#pragma once
+
+namespace tt::lvgl {
+
+/**
+ * @brief Starts listening for KEYBOARD_TYPE kernel devices being started/stopped at runtime
+ * (e.g. a USB HID keyboard being plugged in/out) and binds/unbinds each one to LVGL via
+ * lvgl_keyboard_add()/lvgl_keyboard_remove().
+ *
+ * Devices already started before this is called are picked up by lvgl-module's own boot-time
+ * scan instead (see Modules/lvgl-module/source/devices/devices.cpp's lvgl_devices_attach()) -
+ * this only reacts to devices that start/stop afterwards.
+ */
+void startKeyboardDeviceListener();
+
+/**
+ * @brief Stops listening and unbinds every KEYBOARD_TYPE device this listener bound to LVGL.
+ */
+void stopKeyboardDeviceListener();
+
+} // namespace tt::lvgl