新增 DebugSerialPort 支持，CommonCenter、CanMv 和 DfPlayer 改用智能指针

Core/App/Center/common_center.hpp

@@ -4,6 +4,7 @@
 #include "../Common/df_player.hpp"
 #include "../Common/ultrasonic.hpp"
 #include "../config.hpp"
+#include "Common/serial_port.hpp"
 
 class CommonCenter {
 public:
@@ -31,4 +32,14 @@ public:
         }
         return *instance;
     }
+
+    static SerialPort& GetDebugSerialPort() {
+        static constexpr auto kLength  = 256;
+        static constexpr auto kTimeout = 1000;
+        static SerialPort* instance    = nullptr;
+        if (instance == nullptr) {
+            instance = new SerialPort(Config::kDebugUart, kLength, kTimeout);
+        }
+        return *instance;
+    }
 };