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.

Firmware/CMakeLists.txt

@@ -36,14 +36,13 @@ else ()
         TactilityCore
         TactilityFreeRtos
         TactilityKernel
-        hal-device
+        hal-device-module
+        lvgl-module
         Simulator
         PlatformPosix
         SDL2::SDL2-static SDL2-static
     )
 
-    add_definitions(-D_Nullable=)
-    add_definitions(-D_Nonnull=)
 endif ()
 
 add_custom_target(AlwaysRun