Device cleanup (#592)

- Replaced device_find_\* usage by device_get_\* variants.
- Removed deprecated device_find_\* functions.
- Improved reliability of Bluetooth scanning, pairing, connection, and HID host lifecycle behavior, including peer auto-connect handling.
- Improved Bluetooth/USB status indicators and clarified “Eject failed” alerts with the affected mount path.

Tactility/Source/app/keyboard/KeyboardSettings.cpp

@@ -28,9 +28,10 @@ static uint32_t timeoutMsToIndex(uint32_t ms) {
 
 static void applyKeyboardBacklight(bool enabled, uint8_t brightness) {
     // TODO: Get keyboard backlight from (optional) keyboard child device
-    Device* backlight = device_find_by_name("keyboard_backlight");
-    if (backlight != nullptr) {
+    Device* backlight;
+    if (device_get_by_name("keyboard_backlight", &backlight) == ERROR_NONE) {
         backlight_set_brightness(backlight, enabled ? brightness : 0);
+        device_put(backlight);
     }
 }