新增 DfPlayer 和 CanMv 类，优化 UART 读写方法，更新 CommonCenter 以支持新类实例化

Core/App/Common/df_player.cpp

@@ -0,0 +1,41 @@
+#include "df_player.hpp"
+
+void DfPlayer::SendCommand(Command cmd, uint16_t param) {
+    uint8_t buffer[10];
+    buffer[0] = kStartByte;
+    buffer[1] = kVersion;
+    buffer[2] = 0x06;
+    buffer[3] = static_cast<uint8_t>(cmd);
+    buffer[4] = kFeedback;
+    buffer[5] = (param >> 8) & 0xFF;
+    buffer[6] = param & 0xFF;
+
+    uint16_t checksum = 0xFFFF - (kVersion + 0x06 + static_cast<uint8_t>(cmd) + kFeedback + buffer[5] + buffer[6]) + 1;
+    buffer[7]         = (checksum >> 8) & 0xFF;
+    buffer[8]         = checksum & 0xFF;
+    buffer[9]         = kEndByte;
+
+    serialPort->WriteBytesBlocking(buffer, sizeof(buffer));
+}
+
+void DfPlayer::Play() {
+    SendCommand(Command::kPlay);
+}
+
+void DfPlayer::Stop() {
+    SendCommand(Command::kStop);
+}
+
+void DfPlayer::SetVolume(uint8_t volume) {
+    if (volume > 30) {
+        volume = 30;
+    }
+    SendCommand(Command::kSetVolume, volume);
+}
+
+void DfPlayer::PlayTrack(uint16_t track) {
+    if (track < 1 || track > 2999) {
+        return;
+    }
+    SendCommand(Command::kPlayTrack, track);
+}