feat: 添加第二屏幕及其事件处理功能

- 在 CMakeLists.txt 中添加 ui_Screen2.c 源文件以支持新屏幕
- 新增 ui_events.c 和 ui_events.h，定义按钮点击事件处理函数
- 实现 ui_Screen2.c，构建第二屏幕的 UI 组件和事件回调
- 更新 ui.c 以初始化和加载第二屏幕
- 更新相关头文件，确保新屏幕与现有结构兼容

main/ui/screens/ui_Screen2.h

@@ -0,0 +1,33 @@
+// This file was generated by SquareLine Studio
+// SquareLine Studio version: SquareLine Studio 1.6.1
+// LVGL version: 9.2.2
+// Project name: HeavenlyHeroStar
+
+#ifndef UI_SCREEN2_H
+#define UI_SCREEN2_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// SCREEN: ui_Screen2
+extern void ui_Screen2_screen_init(void);
+extern void ui_Screen2_screen_destroy(void);
+extern lv_obj_t * ui_Screen2;
+extern void ui_event_Button1(lv_event_t * e);
+extern lv_obj_t * ui_Button1;
+extern void ui_event_Button2(lv_event_t * e);
+extern lv_obj_t * ui_Button2;
+extern void ui_event_Button3(lv_event_t * e);
+extern lv_obj_t * ui_Button3;
+extern lv_obj_t * ui_Label2;
+extern lv_obj_t * ui_Label4;
+extern lv_obj_t * ui_Label5;
+// CUSTOM VARIABLES
+
+#ifdef __cplusplus
+} /*extern "C"*/
+#endif
+
+#endif
+