feat: 添加第三屏幕及其音量控制功能

- 在 CMakeLists.txt 中添加 ui_Screen3.c 源文件以支持新屏幕
- 新增 ui_events.c 和 ui_events.h，定义音量控制按钮的点击事件处理函数
- 实现 ui_Screen3.c，构建第三屏幕的 UI 组件和事件回调
- 更新 ui.c 以初始化和加载第三屏幕
- 修改 ble_hid.c 和 ble_hid.h，添加消费者控制功能以支持音量调节
- 更新相关头文件，确保新屏幕与现有结构兼容

main/ui/screens/ui_Screen3.h

@@ -0,0 +1,41 @@
+// 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_SCREEN3_H
+#define UI_SCREEN3_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// SCREEN: ui_Screen3
+extern void ui_Screen3_screen_init(void);
+extern void ui_Screen3_screen_destroy(void);
+extern lv_obj_t * ui_Screen3;
+extern void ui_event_BtnVolDown(lv_event_t * e);
+extern lv_obj_t * ui_BtnVolDown;
+extern void ui_event_BtnVolUp(lv_event_t * e);
+extern lv_obj_t * ui_BtnVolUp;
+extern void ui_event_BtnMute(lv_event_t * e);
+extern lv_obj_t * ui_BtnMute;
+extern void ui_event_BtnPlayPause(lv_event_t * e);
+extern lv_obj_t * ui_BtnPlayPause;
+extern void ui_event_BtnPrev(lv_event_t * e);
+extern lv_obj_t * ui_BtnPrev;
+extern void ui_event_BtnNext(lv_event_t * e);
+extern lv_obj_t * ui_BtnNext;
+extern lv_obj_t * ui_LabelVolDown;
+extern lv_obj_t * ui_LabelVolUp;
+extern lv_obj_t * ui_LabelMute;
+extern lv_obj_t * ui_LabelPlayPause;
+extern lv_obj_t * ui_LabelPrev;
+extern lv_obj_t * ui_LabelNext;
+// CUSTOM VARIABLES
+
+#ifdef __cplusplus
+} /*extern "C"*/
+#endif
+
+#endif