fix: voice message display, playback, recording UI, audio settings

- messagelist: parse content_type from JSON when DB column is empty
- messagelist: recording indicator (red dot + timer + cancel button)
- messagedelegate: editorEvent for play/pause toggle + progress bar
- messagedelegate: VoicePlayState tracking with QTimer
- InputBar: proper recordingContext (mediaDir + channelId)
- DbManager: dbPath() for media directory resolution
- AudioRecorder: peakLevel() for mic level meter
- VoiceEncoder: codec quality presets (Low/Standard/High)
- audiodevicesettingspage: Default device option first
- audiodevicesettingspage: mic level meter + test microphone
- audiodevicesettingspage: test speaker button
- audiodevicesettingspage: codec preset combo (Low/Standard/High)
- mainwindow: load opus_codec_preset from ui_state on startup

tools/chatgui/src/inputbar.cpp

@@ -154,6 +154,11 @@ void InputBar::onSendClicked() {
 #include "audiorecorder.h"
 #include "voicemessageencoder.h"
 
+void InputBar::setRecordingContext(const QString& mediaDirBase, const QString& channelId) {
+    m_mediaDirBase = mediaDirBase;
+    m_channelIdForRecord = channelId;
+}
+
 void InputBar::onPttPressed() {
     if (!m_recorder || !m_recorder->isInitialized()) return;
     m_recorder->startRecording();
@@ -179,9 +184,7 @@ void InputBar::onPttReleased() {
     const std::vector<int16_t>& pcm = m_recorder->buffer();
     if (pcm.empty()) return;
 
-    QString mediaPath = VoiceEncoder::mediaDir(
-        QString::fromUtf8(qgetenv("CHAT_DATA_DIR").isEmpty() ? "chat_data" : qgetenv("CHAT_DATA_DIR")),
-        "current");
+    QString mediaPath = m_mediaDirBase + "/" + m_channelIdForRecord;
     VoiceEncoder::ensureMediaDir(mediaPath);
 
     QString fileName = VoiceEncoder::generateFileName();