v1.8.0: Audio 代码重构与低功耗优化 (#943)

* Reconstruct Audio Code

* Remove old IoT implementation

* Add MQTT-UDP documentation

* OTA升级失败时，可以继续使用

main/display/display.h

@@ -7,6 +7,7 @@
 #include <esp_pm.h>
 
 #include <string>
+#include <chrono>
 
 struct DisplayFonts {
     const lv_font_t* text_font = nullptr;
@@ -29,6 +30,7 @@ public:
     virtual void SetTheme(const std::string& theme_name);
     virtual std::string GetTheme() { return current_theme_name_; }
     virtual void UpdateStatusBar(bool update_all = false);
+    virtual void ShowStandbyScreen(bool show);
 
     inline int width() const { return width_; }
     inline int height() const { return height_; }
@@ -55,6 +57,7 @@ protected:
     bool muted_ = false;
     std::string current_theme_name_;
 
+    std::chrono::system_clock::time_point last_status_update_time_;
     esp_timer_handle_t notification_timer_ = nullptr;
 
     friend class DisplayLockGuard;