Enhance EInkDisplayHandler and LVGLHandler with deep sleep functionality and partial refresh improvements

main/display/lvgl_handler.h

@@ -7,7 +7,6 @@
 #include "esp_err.h"
 #include <memory>
 
-
 class LVGLHandler {
 public:
   LVGLHandler(
@@ -34,6 +33,8 @@ private:
   lv_draw_buf_t* lvgl_draw_buf_ = nullptr;
   uint8_t* framebuffer_ = nullptr;
   bool framebuffer_in_psram_ = false;
+  RefreshArea refresh_area_ = { 0, 0, 0, 0 };
+
 
   SemaphoreHandle_t lvgl_mutex_ = nullptr;
 };