chore: remove CW decoder module (Morse Expert)

Removes the CW decoder entirely. The feature/cw module was a verbatim
decompilation of Morse Expert 1.15 (VE3NEA, a paid Play Store app),
shipped without licence or attribution, and restricted to the armeabi-v7a
ABI only -- which blocks Google Play distribution (64-bit required since
2019-08).

Deleted:
- feature/cw: 11,519 lines of obfuscated decompiled Java,
  libnativedecoderjni.so, layouts and resources
- core/domain/cw: 998 lines of unreachable Kotlin DSP plus its 300-line
  test (CwStartListening and friends were never dispatched by any UI)

Cleaned up in feature/radar:
- Removed CwDecoderPanel, CwSubState, CwStatus and 6 CW actions
- Removed the CW branches and decoder plumbing from RadarViewModel
- Dropped now-unused dependencies: :feature:cw, :feature:mutual (was
  declared but never imported), androidx.constraintlayout
- Removed radar_cw_* strings from en and zh

Kept deliberately: IAudioCapture, audioCapture and the RECORD_AUDIO
permission -- these are shared with SSTV and must not be removed.

CW decoding is gone until it is rewritten. See branch for the deleted
implementation if you need to reference it.

feature/radar/src/main/java/com/rtbishop/look4sat/feature/radar/RadarScreen.kt

@@ -119,13 +119,11 @@ fun RadarDestination(navigateUp: () -> Unit, navigateToMap: () -> Unit) {
     ) == PackageManager.PERMISSION_GRANTED
     LaunchedEffect(hasPermission) {
         viewModel.onAction(RadarAction.SstvPermissionResult(hasPermission))
-        viewModel.onAction(RadarAction.CwPermissionResult(hasPermission))
     }
     val permissionLauncher = rememberLauncherForActivityResult(
         ActivityResultContracts.RequestPermission()
     ) { granted ->
         viewModel.onAction(RadarAction.SstvPermissionResult(granted))
-        viewModel.onAction(RadarAction.CwPermissionResult(granted))
     }
     RadarScreen(uiState, viewModel::onAction, navigateUpAndClearMutual, navigateToMapAndClearMutual, mutualData, requestMicPermission = {
         permissionLauncher.launch(Manifest.permission.RECORD_AUDIO)
@@ -252,10 +250,8 @@ private fun PagerCard(
                         transceivers = uiState.transceivers.transmitters,
                         selectedUuid = uiState.transceivers.selectedUuid,
                         orbitalPos = uiState.orbitalPos,
-                        cw = uiState.cw,
                         calculatorOffsetKHz = uiState.calculatorOffsetKHz,
-                        onAction = onAction,
-                        requestMicPermission = requestMicPermission
+                        onAction = onAction
                     )
                     RadarPage.Sstv -> SstvPage(
                         sstv = uiState.sstv,

feature/radar/src/main/java/com/rtbishop/look4sat/feature/radar/RadarState.kt

@@ -63,7 +63,6 @@ data class RadarState(
     val transceivers: TransceiverSubState = TransceiverSubState(),
     val radioControl: RadioControlSubState = RadioControlSubState(),
     val sstv: SstvSubState = SstvSubState(),
-    val cw: CwSubState = CwSubState(),
     val mutualSamples: List<Pair<Long, Pair<Double, Double>>> = emptyList(),
     val mutualStartTime: Long = 0L,
     val mutualEndTime: Long = 0L,
@@ -85,19 +84,6 @@ data class SstvSubState(
     val diagnosticsMetrics: SstvQualityMetrics? = null
 )
 
-// --- CW Decoder ---
-
-enum class CwStatus { Idle, Listening }
-
-data class CwSubState(
-    val status: CwStatus = CwStatus.Idle,
-    val hasPermission: Boolean = false,
-    val decodedText: String = "",
-    val cwToneFreq: Float = 700f,
-    val isExpanded: Boolean = false,
-    val signalStrength: Float = 0f
-)
-
 sealed interface RadarAction {
     data class AddToCalendar(val name: String, val aosTime: Long, val losTime: Long) : RadarAction
     data class SelectTransmitter(val uuid: String) : RadarAction
@@ -118,14 +104,6 @@ sealed interface RadarAction {
     data class SstvSelectMode(val modeName: String) : RadarAction
     data class SstvPermissionResult(val granted: Boolean) : RadarAction
 
-    // CW actions
-    data object CwStartListening : RadarAction
-    data object CwStopListening : RadarAction
-    data object CwReset : RadarAction
-    data class CwSetToneFreq(val freq: Float) : RadarAction
-    data class CwToggleExpanded(val expanded: Boolean) : RadarAction
-    data class CwPermissionResult(val granted: Boolean) : RadarAction
-
     // Calculator actions
     data class ChangeCalculatorOffset(val offsetKHz: String) : RadarAction
 }

feature/radar/src/main/java/com/rtbishop/look4sat/feature/radar/RadarViewModel.kt

@@ -34,7 +34,6 @@ import com.rtbishop.look4sat.core.domain.repository.ISensorsRepo
 import com.rtbishop.look4sat.core.domain.repository.ISettingsRepo
 import com.rtbishop.look4sat.core.domain.sstv.LineRecoveryStrategy
 import com.rtbishop.look4sat.core.domain.sstv.SstvDecoder
-import com.rtbishop.look4sat.core.domain.cw.CwDecoder
 import com.rtbishop.look4sat.core.domain.usecase.IAudioCapture
 import com.rtbishop.look4sat.core.domain.usecase.IAddToCalendar
 import com.rtbishop.look4sat.core.domain.usecase.ISaveImage
@@ -71,8 +70,6 @@ class RadarViewModel(
     private var transponders: List<SatRadio> = emptyList()
     private var sstvDecoder: SstvDecoder? = null
     private var sstvRecordingJob: Job? = null
-    private var cwDecoder: CwDecoder? = null
-    private var cwListeningJob: Job? = null
 
     // Celestial positions change slowly, recompute at most once per minute
     private var lastCelestialUpdateMs = 0L
@@ -293,24 +290,6 @@ class RadarViewModel(
                 _uiState.update { it.copy(sstv = it.sstv.copy(currentFrame = null)) }
             }
 
-            // CW actions
-            is RadarAction.CwPermissionResult -> {
-                _uiState.update { it.copy(cw = it.cw.copy(hasPermission = action.granted)) }
-                if (action.granted) initCwDecoder()
-            }
-            RadarAction.CwStartListening -> startCwListening()
-            RadarAction.CwStopListening -> stopCwListening()
-            RadarAction.CwReset -> {
-                cwDecoder?.resetDecoder()
-                _uiState.update { it.copy(cw = it.cw.copy(decodedText = "")) }
-            }
-            is RadarAction.CwSetToneFreq -> {
-                _uiState.update { it.copy(cw = it.cw.copy(cwToneFreq = action.freq)) }
-                cwDecoder = CwDecoder(sampleRate = audioCapture.sampleRate, cwToneFreq = action.freq)
-            }
-            is RadarAction.CwToggleExpanded -> {
-                _uiState.update { it.copy(cw = it.cw.copy(isExpanded = action.expanded)) }
-            }
             is RadarAction.ChangeCalculatorOffset -> {
                 val catnum = _uiState.value.transceivers.selectedUuid?.let { uuid ->
                     transponders.find { it.uuid == uuid }?.catnum
@@ -440,52 +419,6 @@ class RadarViewModel(
         _uiState.update { it.copy(sstv = it.sstv.copy(status = SstvStatus.Idle)) }
     }
 
-    private fun initCwDecoder() {
-        if (cwDecoder == null) {
-            cwDecoder = CwDecoder(
-                sampleRate = audioCapture.sampleRate,
-                cwToneFreq = _uiState.value.cw.cwToneFreq
-            )
-        }
-    }
-
-    private fun startCwListening() {
-        if (cwListeningJob?.isActive == true) return
-        if (!_uiState.value.cw.hasPermission) {
-            // Permission not yet granted — request it (launcher handles the result)
-            return
-        }
-        // Stop SSTV if running (audio capture is shared)
-        stopSstvRecording()
-        initCwDecoder()
-        cwDecoder?.resetDecoder()
-        _uiState.update { it.copy(cw = it.cw.copy(status = CwStatus.Listening)) }
-        cwListeningJob = viewModelScope.launch {
-            // Collect decoded text flow
-            launch {
-                cwDecoder?.decodedTextFlow?.collect { text ->
-                    _uiState.update { it.copy(cw = it.cw.copy(decodedText = text)) }
-                }
-            }
-            // Collect signal strength
-            launch {
-                cwDecoder?.signalStrength?.collect { strength ->
-                    _uiState.update { it.copy(cw = it.cw.copy(signalStrength = strength)) }
-                }
-            }
-            // Capture audio and feed to decoder
-            audioCapture.audioFlow().collect { buffer ->
-                cwDecoder?.processBuffer(buffer)
-            }
-        }
-    }
-
-    private fun stopCwListening() {
-        cwListeningJob?.cancel()
-        cwListeningJob = null
-        _uiState.update { it.copy(cw = it.cw.copy(status = CwStatus.Idle)) }
-    }
-
     companion object {
         // SSTV Decoder Tuning Parameters
         // ==============================

feature/radar/src/main/java/com/rtbishop/look4sat/feature/radar/TransceiversPage.kt

@@ -17,8 +17,6 @@
  */
 package com.rtbishop.look4sat.feature.radar
 
-import android.app.Activity
-import android.view.LayoutInflater
 import androidx.compose.animation.AnimatedVisibility
 import androidx.compose.animation.expandVertically
 import androidx.compose.animation.shrinkVertically
@@ -49,7 +47,6 @@ import androidx.compose.foundation.lazy.rememberLazyListState
 import androidx.compose.foundation.shape.CircleShape
 import androidx.compose.foundation.layout.PaddingValues
 import androidx.compose.foundation.text.KeyboardOptions
-import androidx.compose.material3.Button
 import androidx.compose.material3.FilterChip
 import androidx.compose.material3.HorizontalDivider
 import androidx.compose.material3.Icon
@@ -62,7 +59,6 @@ import androidx.compose.material3.TextButton
 import androidx.compose.material3.ElevatedCard
 import androidx.compose.material3.CardDefaults
 import androidx.compose.runtime.Composable
-import androidx.compose.runtime.DisposableEffect
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableIntStateOf
@@ -77,7 +73,6 @@ import androidx.compose.ui.draw.drawBehind
 import androidx.compose.ui.draw.rotate
 import androidx.compose.ui.geometry.Offset
 import androidx.compose.ui.graphics.Color
-import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.res.painterResource
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.text.TextStyle
@@ -87,8 +82,6 @@ import androidx.compose.ui.text.style.TextAlign
 import androidx.compose.ui.text.style.TextOverflow
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
-import androidx.compose.ui.viewinterop.AndroidView
-import androidx.constraintlayout.widget.ConstraintLayout
 import com.rtbishop.look4sat.core.domain.model.SatRadio
 import com.rtbishop.look4sat.core.domain.predict.OrbitalPos
 import com.rtbishop.look4sat.core.domain.utility.DopplerFrequencyCalculator
@@ -96,8 +89,6 @@ import com.rtbishop.look4sat.core.presentation.CardButton
 import com.rtbishop.look4sat.core.presentation.R
 import com.rtbishop.look4sat.core.presentation.formatFrequency
 import com.rtbishop.look4sat.core.presentation.infiniteMarquee
-import com.rtbishop.look4sat.feature.cw.R as CwR
-import com.ve3nea.morse_expert.MainActivity
 import java.util.Locale
 import kotlin.time.Duration.Companion.milliseconds
 
@@ -143,10 +134,8 @@ fun CalculatorPage(
     transceivers: List<SatRadio>,
     selectedUuid: String?,
     orbitalPos: OrbitalPos?,
-    cw: CwSubState,
     calculatorOffsetKHz: String = "",
     onAction: (RadarAction) -> Unit,
-    requestMicPermission: () -> Unit = {},
     modifier: Modifier = Modifier
 ) {
     val calculatorTransceivers = remember(transceivers) {
@@ -201,17 +190,6 @@ fun CalculatorPage(
             modifier = Modifier.fillMaxWidth()
         )
 
-        HorizontalDivider(
-            thickness = 1.dp,
-            color = MaterialTheme.colorScheme.outline.copy(alpha = 0.3f)
-        )
-
-        CwDecoderPanel(
-            cw = cw,
-            onAction = onAction,
-            requestMicPermission = requestMicPermission,
-            modifier = Modifier.fillMaxWidth()
-        )
     }
 }
 
@@ -903,130 +881,6 @@ private fun DopplerFrequencyCalculator(
         }
 }
 
-@Composable
-private fun CwDecoderPanel(
-    cw: CwSubState,
-    onAction: (RadarAction) -> Unit,
-    requestMicPermission: () -> Unit = {},
-    modifier: Modifier = Modifier
-) {
-    Column(
-        modifier = modifier,
-        verticalArrangement = Arrangement.spacedBy(4.dp)
-    ) {
-        // Header row: expand/collapse toggle
-        Row(
-            modifier = Modifier
-                .fillMaxWidth()
-                .clickable { onAction(RadarAction.CwToggleExpanded(!cw.isExpanded)) },
-            horizontalArrangement = Arrangement.SpaceBetween,
-            verticalAlignment = Alignment.CenterVertically
-        ) {
-            Text(
-                text = stringResource(R.string.radar_cw_decoder),
-                fontSize = 14.sp,
-                fontWeight = FontWeight.Medium,
-                color = MaterialTheme.colorScheme.primary
-            )
-            Icon(
-                painter = painterResource(id = R.drawable.ic_arrow),
-                contentDescription = null,
-                tint = MaterialTheme.colorScheme.onSurfaceVariant,
-                modifier = Modifier
-                    .size(20.dp)
-                    .rotate(if (cw.isExpanded) 270f else 90f)
-            )
-        }
-
-        AnimatedVisibility(visible = cw.isExpanded) {
-            // PR #1 Morse Expert engine: mini layout with waterfall + decoded text.
-            // Keep the old Kotlin decoder state/actions as fallback code, but this panel no longer feeds it.
-            val context = LocalContext.current
-            val activity = remember(context) {
-                context as? Activity ?: error("CwDecoderPanel must be hosted in an Activity")
-            }
-            val controller = remember { MainActivity() }
-            val rootView = remember(context) {
-                LayoutInflater.from(context).inflate(CwR.layout.activity_main, null) as ConstraintLayout
-            }
-            var initialized by remember { mutableStateOf(false) }
-            var listening by remember { mutableStateOf(false) }
-
-            // 重要: 不在展开时初始化控制器(避免"一展开就崩溃")。
-            // controller.onCreate/onResume/onPermissionGranted 全部推迟到用户点 Start 才执行。
-            fun startDecoding() {
-                if (!initialized) {
-                    controller.onCreate(activity, rootView)
-                    controller.onPermissionGranted()
-                    controller.onResume()
-                    initialized = true
-                } else {
-                    controller.onResume()
-                }
-                listening = true
-            }
-
-            DisposableEffect(Unit) {
-                onDispose {
-                    if (initialized) {
-                        controller.onPause()
-                        controller.onDestroy()
-                    }
-                }
-            }
-
-            Column(verticalArrangement = Arrangement.spacedBy(8.dp)) {
-                Row(
-                    horizontalArrangement = Arrangement.spacedBy(8.dp),
-                    modifier = Modifier.fillMaxWidth()
-                ) {
-                    if (!listening) {
-                        Button(
-                            onClick = {
-                                if (!cw.hasPermission) {
-                                    requestMicPermission()
-                                } else {
-                                    startDecoding()
-                                }
-                            },
-                            modifier = Modifier.weight(1f)
-                        ) {
-                            Text(stringResource(R.string.radar_cw_start))
-                        }
-                    } else {
-                        Button(
-                            onClick = {
-                                controller.onPause()
-                                listening = false
-                            },
-                            modifier = Modifier.weight(1f)
-                        ) {
-                            Text(stringResource(R.string.radar_cw_stop))
-                        }
-                    }
-                    OutlinedButton(
-                        onClick = { if (initialized) controller.clearDecoded() },
-                        modifier = Modifier.weight(1f)
-                    ) {
-                        Text(stringResource(R.string.radar_cw_reset))
-                    }
-                }
-
-                Box(
-                    modifier = Modifier
-                        .fillMaxWidth()
-                        .height(150.dp)
-                ) {
-                    AndroidView(
-                        factory = { rootView },
-                        modifier = Modifier.fillMaxSize()
-                    )
-                }
-            }
-        }
-    }
-}
-
 @Composable
 private fun FrequencyText(frequency: Long?, modifier: Modifier = Modifier) {
     val text = frequency?.let {