Refactor LVGL code into kernel module (#472)

* **New Features**
  * Added a standalone LVGL module and enabled LVGL support in the simulator for richer local UI testing.

* **Refactor**
  * HAL and LVGL split into distinct modules; startup and device attach/detach flows reorganized for clearer lifecycle management.
  * Public APIs tightened with clearer nullability/documentation.

* **Bug Fixes**
  * More consistent LVGL start/stop and device attach/detach behavior for improved stability.

Tests/TactilityKernel/DeviceTest.cpp

@@ -167,10 +167,10 @@ TEST_CASE("device_is_ready should return true only when it is started") {
     Driver driver = {
         .name = "test_driver",
         .compatible = compatible,
-        .startDevice = nullptr,
-        .stopDevice = nullptr,
+        .start_device = nullptr,
+        .stop_device = nullptr,
         .api = nullptr,
-        .deviceType = nullptr,
+        .device_type = nullptr,
         .owner = &module,
         .driver_private = nullptr
     };