fix(mqtt): address bugs found by ultra code-review and smoke testing

Six fixes from /code-review ultra:
- startKissTncOnStartupIfConfigured: call setMqttClient() so
  auto-started KISS TNC has MQTT wired up
- kCwDecodeTopic: set defaultEnabled=true so upgrades don't silently
  disable previously-always-on CW decode
- routeCwDecoderOutput: save m_cwStatsConn handle to properly
  disconnect statsUpdated lambda (connection leak)
- handleMqttMessage: add isVisible() guard so hidden dialog can't
  key the radio via MQTT
- publishFrameMqtt: add isMqttTopicEnabled(kAx25RxTopic) guard
- cw/transmit: save/restore cwSpeed/cwPitch after MQTT-commanded TX

Four fixes from smoke testing:
- queueEmpty doesn't fire with sync_cwx=0; replace with 1-second
  debounce timer (m_cwxTxEndTimer) — queueEmpty kept as fast path
- Speed restore uses cwxModel().setSpeed() (cwx wpm N); CWX ignores
  transmitModel().setCwSpeed() (cw wpm N)
- radio/state publishes one tx:true at keying start and one
  tx:false after 1 s silence, suppressing inter-element transitions
- Remove flooding "MQTT CW decode suppressed" debug log

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: K5PTB

src/core/MqttSettings.cpp

@@ -303,7 +303,7 @@ const QVector<InternalMqttTopicDef>& internalMqttSubscribeTopicDefs()
 const QVector<InternalMqttTopicDef>& internalMqttPublishTopicDefs()
 {
     static const QVector<InternalMqttTopicDef> defs = {
-        { QString(kCwDecodeTopic),    QStringLiteral("CW decoded text"),             true },
+        { QString(kCwDecodeTopic),    QStringLiteral("CW decoded text"),             true, true },
         { QString(kRadioStateTopic),  QStringLiteral("Radio VFO / mode / TX state"), true },
         { QString(kAx25RxTopic),      QStringLiteral("AX.25 received frames"),       true },
     };
@@ -325,12 +325,12 @@ bool isMqttTopicEnabled(const QString& topic)
     for (const auto& def : internalMqttSubscribeTopicDefs()) {
         if (def.topic == topic)
             return !def.gateable || AppSettings::instance()
-                .value(topicEnabledKey(topic), false).toBool();
+                .value(topicEnabledKey(topic), def.defaultEnabled).toBool();
     }
     for (const auto& def : internalMqttPublishTopicDefs()) {
         if (def.topic == topic)
             return !def.gateable || AppSettings::instance()
-                .value(topicEnabledKey(topic), false).toBool();
+                .value(topicEnabledKey(topic), def.defaultEnabled).toBool();
     }
     return false;
 }

src/core/MqttSettings.h

@@ -59,7 +59,8 @@ inline constexpr QLatin1String kAx25TxTopic     {"aethersdr/ax25/tx"};
 struct InternalMqttTopicDef {
     QString topic;
     QString description;
-    bool    gateable{true};  // false = always on, not user-disableable
+    bool    gateable{true};        // false = always on, not user-disableable
+    bool    defaultEnabled{false}; // true = on by default (for topics always-on before per-topic gating was added)
 };
 
 const QVector<InternalMqttTopicDef>& internalMqttSubscribeTopicDefs();

src/gui/Ax25HfPacketDecodeDialog.cpp

@@ -1356,6 +1356,8 @@ void Ax25HfPacketDecodeDialog::publishFrameMqtt(const Ax25DecodedFrame& frame)
 {
     if (!m_mqtt)
         return;
+    if (!isMqttTopicEnabled(QString::fromLatin1(kAx25RxTopic)))
+        return;
     QString display = frame.source + QStringLiteral(">") + frame.destination;
     if (!frame.path.isEmpty())
         display += QStringLiteral(",") + frame.path.join(QStringLiteral(","));
@@ -1380,6 +1382,8 @@ void Ax25HfPacketDecodeDialog::handleMqttMessage(const QString& topic, const QBy
         return;
     if (!isMqttTopicEnabled(QString::fromLatin1(kAx25TxTopic)))
         return;
+    if (!isVisible())
+        return;
     startTransmit(QString::fromUtf8(payload).trimmed());
 }
 #endif

src/gui/MainWindow.cpp

@@ -2010,6 +2010,18 @@ MainWindow::MainWindow(QWidget* parent)
     // Slice freq/mode changes are wired per-slice in setActiveSliceInternal().
     connect(&m_radioModel, &RadioModel::radioTransmittingChanged,
             this, [this](bool) { publishRadioStateMqtt(); });
+    // Debounce timer for end-of-CWX detection (queueEmpty unreliable with sync_cwx=0).
+    // Fires 1 s after the last tx:false with no intervening tx:true = transmission done.
+    m_cwxTxEndTimer.setSingleShot(true);
+    connect(&m_cwxTxEndTimer, &QTimer::timeout, this, [this]() {
+        if (m_cwxSavedWpm > 0) m_radioModel.cwxModel().setSpeed(m_cwxSavedWpm);
+        if (m_cwxSavedHz  > 0) m_radioModel.transmitModel().setCwPitch(m_cwxSavedHz);
+        m_cwxSavedWpm = 0;
+        m_cwxSavedHz  = 0;
+        m_cwxTransmitting = false;
+        m_cwxPublishedTxTrue = false;
+        publishRadioStateMqtt();
+    });
 
     // aethersdr/cw/transmit → CWX keyer.
     // Payload: {"text":"de k5ptb","speed_wpm":28,"pitch_hz":600}
@@ -2024,10 +2036,34 @@ MainWindow::MainWindow(QWidget* parent)
         if (text.isEmpty()) return;
         auto& tx = m_radioModel.transmitModel();
         const int wpm = obj.value(QStringLiteral("speed_wpm")).toInt(0);
-        if (wpm >= 5 && wpm <= 100) tx.setCwSpeed(wpm);
-        const int hz = obj.value(QStringLiteral("pitch_hz")).toInt(0);
-        if (hz >= 100 && hz <= 6000) tx.setCwPitch(hz);
+        const int hz  = obj.value(QStringLiteral("pitch_hz")).toInt(0);
+        const bool changeWpm = (wpm >= 5 && wpm <= 100);
+        const bool changeHz  = (hz >= 100 && hz <= 6000);
+        m_cwxSavedWpm = changeWpm ? m_radioModel.cwxModel().speed() : 0;
+        m_cwxSavedHz  = changeHz  ? tx.cwPitch() : 0;
+        if (changeWpm) m_radioModel.cwxModel().setSpeed(wpm);
+        if (changeHz)  tx.setCwPitch(hz);
+        m_cwxTxEndTimer.stop();
+        m_cwxPublishedTxTrue = false;
+        m_cwxTransmitting = true;
         m_radioModel.cwxModel().send(text);
+        disconnect(m_cwxSpeedRestoreConn);
+        m_cwxSpeedRestoreConn = connect(
+            &m_radioModel.cwxModel(), &CwxModel::queueEmpty,
+            this, [this]() {
+                // Fast path if queueEmpty fires (sync_cwx=1 or firmware sends queue=0).
+                // Identical work to m_cwxTxEndTimer.timeout — whichever fires first wins.
+                if (m_cwxSavedWpm > 0) m_radioModel.cwxModel().setSpeed(m_cwxSavedWpm);
+                if (m_cwxSavedHz  > 0) m_radioModel.transmitModel().setCwPitch(m_cwxSavedHz);
+                m_cwxSavedWpm = 0;
+                m_cwxSavedHz  = 0;
+                m_cwxTxEndTimer.stop();
+                m_cwxTransmitting = false;
+                m_cwxPublishedTxTrue = false;
+                if (!m_radioModel.isRadioTransmitting())
+                    publishRadioStateMqtt();
+                disconnect(m_cwxSpeedRestoreConn);
+            });
     });
 
     // MQTT → panadapter overlay display
@@ -6014,10 +6050,8 @@ void MainWindow::publishCwDecodeMqtt(const QString& text, float cost, bool rx)
     if (!m_mqttClient) return;
     if (!isMqttTopicEnabled(QString::fromLatin1(kCwDecodeTopic))) return;
     // No CW panel active → nothing is displayed → don't publish.
-    if (!m_cwDecoderApplet || cost >= m_cwDecoderApplet->cwCostThreshold()) {
-        qCDebug(lcMqtt) << "MQTT CW decode suppressed: no applet or cost threshold";
+    if (!m_cwDecoderApplet || cost >= m_cwDecoderApplet->cwCostThreshold())
         return;
-    }
     // Mirror panel normalization: \n → space; drop whitespace-only TX chunks.
     QString clean = text;
     clean.replace(QLatin1Char('\n'), QLatin1Char(' '));
@@ -6043,6 +6077,15 @@ void MainWindow::publishRadioStateMqtt()
 {
     if (!m_mqttClient) return;
     if (!isMqttTopicEnabled(QString::fromLatin1(kRadioStateTopic))) return;
+    if (m_cwxTransmitting) {
+        if (!m_radioModel.isRadioTransmitting()) {
+            m_cwxTxEndTimer.start(1000);  // might be done; confirm after 1 s silence
+            return;
+        }
+        m_cwxTxEndTimer.stop();           // element started — not done yet
+        if (m_cwxPublishedTxTrue) return;
+        m_cwxPublishedTxTrue = true;
+    }
     auto* s = activeSlice();
     if (!s) return;
     QJsonObject obj;
@@ -6892,6 +6935,9 @@ void MainWindow::startKissTncOnStartupIfConfigured()
         AppSettings::instance().value("FramelessWindow", "True").toString() == "True");
     m_ax25HfPacketDecodeDialog = dlg;
     m_persistentDialogs.append(QPointer<PersistentDialog>(dlg));
+#ifdef HAVE_MQTT
+    m_ax25HfPacketDecodeDialog->setMqttClient(m_mqttClient);
+#endif
 }
 
 void MainWindow::showFlexControlDialog()
@@ -13100,6 +13146,7 @@ void MainWindow::routeCwDecoderOutput()
     if (target == m_cwDecoderApplet) return;
 
     // Disconnect from old applet
+    disconnect(m_cwStatsConn);
     if (m_cwDecoderApplet) {
         disconnect(&m_cwDecoder, &CwDecoder::textDecoded,
                    m_cwDecoderApplet, &PanadapterApplet::appendCwText);
@@ -13135,7 +13182,7 @@ void MainWindow::routeCwDecoderOutput()
                 m_cwDecoderApplet, &PanadapterApplet::appendCwTextTx);
         connect(&m_cwDecoder, &CwDecoder::statsUpdated,
                 m_cwDecoderApplet, &PanadapterApplet::setCwStats);
-        connect(&m_cwDecoder, &CwDecoder::statsUpdated,
+        m_cwStatsConn = connect(&m_cwDecoder, &CwDecoder::statsUpdated,
                 this, [this](float pitchHz, float speedWpm) {
             m_cwLastPitchHz   = pitchHz;
             m_cwLastSpeedWpm  = speedWpm;

src/gui/MainWindow.h

@@ -484,6 +484,13 @@ private slots:
     QMetaObject::Connection m_radioStateFreqConn;
     QMetaObject::Connection m_radioStateModeConn;
     QTimer                  m_radioStateCoalesceTimer;
+    QMetaObject::Connection m_cwStatsConn;
+    QMetaObject::Connection m_cwxSpeedRestoreConn;
+    int               m_cwxSavedWpm{0};
+    int               m_cwxSavedHz{0};
+    bool              m_cwxTransmitting{false};
+    bool              m_cwxPublishedTxTrue{false};
+    QTimer            m_cwxTxEndTimer;
     CwDecoder         m_cwDecoderTx;
     RttyDecoder       m_rttyDecoder;
     DxClusterClient*   m_dxCluster{nullptr};