fix(settings): Fix OFF visibility toggle not reacting on first press

Serialize AapConnection.send() with a dedicated sendMutex so two concurrent optimistic state updates cannot clobber each other. Collapse the OFF toggle click into a single combined VM call that runs both SetListeningModeCycle and SetAllowOffOption sequentially.

app/src/main/java/eu/darken/capod/main/ui/devicesettings/DeviceSettingsScreen.kt

@@ -155,6 +155,7 @@ fun DeviceSettingsScreenHost(
         onMicrophoneModeChange = { vm.setMicrophoneMode(it) },
         onListeningModeCycleChange = { vm.setListeningModeCycle(it) },
         onAllowOffOptionChange = { vm.setAllowOffOption(it) },
+        onOffVisibilityChange = { enabled, mask -> vm.setListeningModeOffVisibility(enabled, mask) },
         onSleepDetectionChange = { vm.setSleepDetection(it) },
         onDeviceNameChange = { vm.setDeviceName(it) },
         onStemActionsClick = { vm.navToStemConfig() },
@@ -190,6 +191,7 @@ fun DeviceSettingsScreen(
     onMicrophoneModeChange: (AapSetting.MicrophoneMode.Mode) -> Unit = {},
     onListeningModeCycleChange: (Int) -> Unit = {},
     onAllowOffOptionChange: (Boolean) -> Unit = {},
+    onOffVisibilityChange: (enabled: Boolean, currentCycleMask: Int) -> Unit = { _, _ -> },
     onSleepDetectionChange: (Boolean) -> Unit = {},
     onDeviceNameChange: (String) -> Unit = {},
     onStemActionsClick: () -> Unit = {},
@@ -402,6 +404,7 @@ fun DeviceSettingsScreen(
                             cycleMask = if (isPro) cycleMask else null,
                             onCycleMaskChange = onListeningModeCycleChange,
                             onAllowOffChange = onAllowOffOptionChange,
+                            onOffVisibilityChange = onOffVisibilityChange,
                             enabled = enabled,
                         )
                     }
@@ -1253,6 +1256,7 @@ private fun NoiseControlCombined(
     cycleMask: Int?,
     onCycleMaskChange: (Int) -> Unit,
     onAllowOffChange: (Boolean) -> Unit = {},
+    onOffVisibilityChange: (enabled: Boolean, currentCycleMask: Int) -> Unit = { _, _ -> },
     enabled: Boolean,
 ) {
     val displayMode = pendingMode ?: currentMode
@@ -1288,12 +1292,12 @@ private fun NoiseControlCombined(
                         IconButton(
                             onClick = {
                                 val isOff = mode == AapSetting.AncMode.Value.OFF
-                                if (inCycle == true && canRemoveFromCycle) {
+                                if (isOff) {
+                                    onOffVisibilityChange(inCycle != true, cycleMask ?: 0)
+                                } else if (inCycle == true && canRemoveFromCycle) {
                                     onCycleMaskChange(cycleMask xor bit)
-                                    if (isOff) onAllowOffChange(false)
                                 } else if (inCycle != true) {
                                     onCycleMaskChange((cycleMask ?: 0) or bit)
-                                    if (isOff) onAllowOffChange(true)
                                 }
                             },
                             enabled = enabled && (inCycle != true || canRemoveFromCycle),

app/src/main/java/eu/darken/capod/main/ui/devicesettings/DeviceSettingsViewModel.kt

@@ -167,14 +167,16 @@ class DeviceSettingsViewModel @Inject constructor(
         }
     }
 
-    private suspend fun sendInternal(command: AapCommand) {
-        val address = currentAddress() ?: return
-        try {
+    private suspend fun sendInternal(command: AapCommand): Boolean {
+        val address = currentAddress() ?: return false
+        return try {
             aapManager.sendCommand(address, command)
             log(TAG) { "Sent $command to $address" }
+            true
         } catch (e: Exception) {
             log(TAG, WARN) { "Failed to send $command: ${e.message}" }
             events.emit(Event.SendFailed(command, e.message))
+            false
         }
     }
 
@@ -223,6 +225,19 @@ class DeviceSettingsViewModel @Inject constructor(
 
     fun setAllowOffOption(enabled: Boolean) = sendProGated(AapCommand.SetAllowOffOption(enabled))
 
+    fun setListeningModeOffVisibility(enabled: Boolean, currentCycleMask: Int) = launch {
+        if (!upgradeRepo.isPro()) {
+            navTo(Nav.Main.Upgrade)
+            return@launch
+        }
+        // Keep in sync with cycleBits[OFF] in DeviceSettingsScreen.NoiseControlCombined
+        val offBit = 0x01
+        val newMask = if (enabled) currentCycleMask or offBit else currentCycleMask and offBit.inv()
+        if (sendInternal(AapCommand.SetListeningModeCycle(newMask))) {
+            sendInternal(AapCommand.SetAllowOffOption(enabled))
+        }
+    }
+
     fun setSleepDetection(enabled: Boolean) = sendProGated(AapCommand.SetSleepDetection(enabled))
 
     fun setDeviceName(name: String) = launch {

app/src/main/java/eu/darken/capod/pods/core/apple/aap/AapConnection.kt

@@ -65,6 +65,7 @@ internal class AapConnection(
     private var socket: BluetoothSocket? = null
     private var readerJob: Job? = null
     private val writeMutex = Mutex()
+    private val sendMutex = Mutex()
     private val framer = AapFramer()
 
     private var pendingAncMode: AapSetting.AncMode.Value? = null
@@ -147,7 +148,7 @@ internal class AapConnection(
         _state.value = AapPodState(connectionState = AapPodState.ConnectionState.DISCONNECTED)
     }
 
-    suspend fun send(command: AapCommand) {
+    suspend fun send(command: AapCommand) = sendMutex.withLock {
         val currentState = _state.value
         if (currentState.connectionState != AapPodState.ConnectionState.READY) {
             throw IllegalStateException("Cannot send command in state ${currentState.connectionState}")
@@ -162,7 +163,7 @@ internal class AapConnection(
                 log(TAG) { "No pod in ear, queuing ANC mode: ${command.mode}" }
                 pendingAncMode = command.mode
                 _state.value = currentState.copy(pendingAncMode = command.mode)
-                return
+                return@withLock
             }
             pendingAncMode = null
             // Optimistically update UI — don't wait for device echo