Apply only the settings keys given, rather than copying the whole settings

These keyed applySettings copied the whole settings struct on every message. A GUI sends
messages with no keys while its window is being laid out, carrying its own copy of the
settings, and one arriving after an API patch but before the GUI has seen it wrote the old
values back, so the patched value was lost and the API read back what it had replaced. The AIS
demodulator lost the inputFrequencyOffset set at creation this way.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

plugins/channelrx/chanalyzer/chanalyzerbaseband.cpp

@@ -161,7 +161,11 @@ void ChannelAnalyzerBaseband::applySettings(const ChannelAnalyzerSettings& setti
     }
 
     m_sink.applySettings(settings, settingsKeys, force);
-    m_settings = settings;
+    if (force) {
+        m_settings = settings;
+    } else {
+        m_settings.applySettings(settingsKeys, settings);
+    }
 }
 
 int ChannelAnalyzerBaseband::getChannelSampleRate() const

plugins/channelrx/demodais/aisdemod.cpp

@@ -324,7 +324,11 @@ void AISDemod::applySettings(const AISDemodSettings& settings, const QStringList
         }
     }
 
-    m_settings = settings;
+    if (force) {
+        m_settings = settings;
+    } else {
+        m_settings.applySettings(settingsKeys, settings);
+    }
 }
 
 QByteArray AISDemod::serialize() const

plugins/channelrx/localsink/localsink.cpp

@@ -395,7 +395,11 @@ void LocalSink::applySettings(const LocalSinkSettings& settings, const QList<QSt
         sendChannelSettings(pipes, settingsKeys, settings, force);
     }
 
-    m_settings = settings;
+    if (force) {
+        m_settings = settings;
+    } else {
+        m_settings.applySettings(settingsKeys, settings);
+    }
 }
 
 void LocalSink::validateFilterChainHash(LocalSinkSettings& settings)

plugins/feature/antennatools/antennatools.cpp

@@ -111,7 +111,11 @@ void AntennaTools::applySettings(const AntennaToolsSettings& settings, const QLi
         webapiReverseSendSettings(settingsKeys, settings, fullUpdate || force);
     }
 
-    m_settings = settings;
+    if (force) {
+        m_settings = settings;
+    } else {
+        m_settings.applySettings(settingsKeys, settings);
+    }
 }
 
 int AntennaTools::webapiSettingsGet(

plugins/feature/aprs/aprs.cpp

@@ -237,7 +237,11 @@ void APRS::applySettings(const APRSSettings& settings, const QList<QString>& set
         webapiReverseSendSettings(settingsKeys, settings, fullUpdate || force);
     }
 
-    m_settings = settings;
+    if (force) {
+        m_settings = settings;
+    } else {
+        m_settings.applySettings(settingsKeys, settings);
+    }
 }
 
 int APRS::webapiRun(bool run,

plugins/feature/jogdialcontroller/jogdialcontroller.cpp

@@ -184,7 +184,11 @@ void JogdialController::applySettings(const JogdialControllerSettings& settings,
         webapiReverseSendSettings(settingsKeys, settings, fullUpdate || force);
     }
 
-    m_settings = settings;
+    if (force) {
+        m_settings = settings;
+    } else {
+        m_settings.applySettings(settingsKeys, settings);
+    }
 }
 
 void JogdialController::updateChannels()

plugins/feature/pertester/pertester.cpp

@@ -206,7 +206,11 @@ void PERTester::applySettings(const PERTesterSettings& settings, const QList<QSt
         webapiReverseSendSettings(settingsKeys, settings, fullUpdate || force);
     }
 
-    m_settings = settings;
+    if (force) {
+        m_settings = settings;
+    } else {
+        m_settings.applySettings(settingsKeys, settings);
+    }
 }
 
 int PERTester::webapiRun(bool run,

plugins/feature/startracker/startracker.cpp

@@ -267,7 +267,11 @@ void StarTracker::applySettings(const StarTrackerSettings& settings, const QList
         webapiReverseSendSettings(settingsKeys, settings, fullUpdate || force);
     }
 
-    m_settings = settings;
+    if (force) {
+        m_settings = settings;
+    } else {
+        m_settings.applySettings(settingsKeys, settings);
+    }
 }
 
 int StarTracker::webapiRun(bool run,

plugins/feature/vorlocalizer/vorlocalizer.cpp

@@ -357,7 +357,11 @@ void VORLocalizer::applySettings(const VORLocalizerSettings& settings, const QLi
         webapiReverseSendSettings(settingsKeys, settings, fullUpdate || force);
     }
 
-    m_settings = settings;
+    if (force) {
+        m_settings = settings;
+    } else {
+        m_settings.applySettings(settingsKeys, settings);
+    }
 }
 
 void VORLocalizer::updateChannels()