fix: pause support + old message skip + stopCurrentPcm

- SoundManager: added stopCurrentPcm() for pause/stop of PCM playback
- messagedelegate: call stopCurrentPcm on pause, new play, and timer complete
- messagelist: skip old double-nested JSON messages (raw starts with '{')
- sound_manager.h: void* for ma_audio_buffer to avoid header dependency

tools/chatgui/src/messagedelegate.cpp

@@ -5,6 +5,7 @@
 #include "animtimer.h"
 #include "lottieicon.h"
 #include "voiceplayback.h"
+#include "sound_manager.h"
 #include <cmath>
 #include <QPainter>
 #include <QPainterPath>
@@ -42,6 +43,7 @@ static void ensureVoiceTimer() {
                 float elapsed = (now - it->startMs) / 1000.0f;
                 if (elapsed >= it->durationSec && it->durationSec > 0) {
                     it->playing = false;
+                    SoundManager::instance()->stopCurrentPcm();
                     ++it;
                 } else {
                     anyPlaying = true;
@@ -76,13 +78,13 @@ bool MessageDelegate::editorEvent(QEvent *event, QAbstractItemModel *model,
 
     if (st.playing) {
         st.playing = false;
+        SoundManager::instance()->stopCurrentPcm();
         model->setData(index, 0, MsgVoicePlayStateRole);
     } else {
-        // Stop any other playing voice
         for (auto it = s_voiceStates.begin(); it != s_voiceStates.end(); ++it)
             it->playing = false;
+        SoundManager::instance()->stopCurrentPcm();
 
-        // Parse duration
         QString durStr = index.data(MsgVoiceDurationRole).toString();
         durStr.remove('s');
         float dur = durStr.toFloat();