feat: replace Doppler calculator panel with slider-based UI

Replace the text-input DopplerCalculatorPanel with the slider-based
DopplerFrequencyCalculator UI: TX/RX sliders with 1kHz step buttons,
offset kHz input, and TX/PASSBAND/RX edit mode. No other changes.

core/data/src/main/java/com/rtbishop/look4sat/core/data/repository/SettingsRepo.kt

@@ -37,7 +37,6 @@ import com.rtbishop.look4sat.core.domain.utility.round
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.update
-import org.json.JSONObject
 
 class SettingsRepo(
     private val locationManager: LocationManager,
@@ -418,27 +417,5 @@ class SettingsRepo(
         baudRate = preferences.getInt(keyRadioBaudRate, 4800),
         splitMode = preferences.getBoolean(keyRadioSplitMode, false)
     )
-
-    private val keySatelliteOffsets = "satelliteOffsets"
-
-    override fun getSatelliteOffset(catnum: Int): String {
-        val json = preferences.getString(keySatelliteOffsets, "{}") ?: "{}"
-        return try {
-            JSONObject(json).optString(catnum.toString(), "")
-        } catch (e: Exception) {
-            ""
-        }
-    }
-
-    override fun setSatelliteOffset(catnum: Int, offset: String) {
-        val json = preferences.getString(keySatelliteOffsets, "{}") ?: "{}"
-        val updated = try {
-            val obj = JSONObject(json)
-            if (offset.isEmpty()) obj.remove(catnum.toString()) else obj.put(catnum.toString(), offset)
-            obj.toString()
-        } catch (e: Exception) {
-            """{"$catnum": "$offset"}"""
-        }
-        preferences.edit { putString(keySatelliteOffsets, updated) }
-    }
+    //endregion
 }

core/data/src/test/java/com/rtbishop/look4sat/core/data/repository/DatabaseRepoTest.kt

@@ -213,10 +213,6 @@ private class FakeSettingsRepo(dataSources: DataSourcesSettings = defaultDataSou
     }
 
     override fun updateRadioControlSettings(settings: RadioControlSettings) = Unit
-
-    override fun getSatelliteOffset(catnum: Int): String = ""
-
-    override fun setSatelliteOffset(catnum: Int, offset: String) = Unit
 }
 
 private fun defaultDataSourcesSettings(): DataSourcesSettings {

core/data/src/test/java/com/rtbishop/look4sat/core/data/repository/SelectionRepoTest.kt

@@ -167,10 +167,6 @@ class SelectionRepoTest {
         override fun updateDataSourcesSettings(settings: DataSourcesSettings) = Unit
 
         override fun updateRadioControlSettings(settings: RadioControlSettings) = Unit
-
-        override fun getSatelliteOffset(catnum: Int): String = ""
-
-        override fun setSatelliteOffset(catnum: Int, offset: String) = Unit
     }
 }
 

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/repository/ISettingsRepo.kt

@@ -75,9 +75,4 @@ interface ISettingsRepo {
     val radioControlSettings: StateFlow<RadioControlSettings>
     fun updateRadioControlSettings(settings: RadioControlSettings)
     //endregion
-
-    //region # Per-satellite calculator offset settings
-    fun getSatelliteOffset(catnum: Int): String
-    fun setSatelliteOffset(catnum: Int, offset: String)
-    //endregion
 }

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

@@ -198,8 +198,7 @@ private fun PagerCard(
                         transceivers = uiState.transceivers.transmitters,
                         selectedUuid = uiState.transceivers.selectedUuid,
                         orbitalPos = uiState.orbitalPos,
-                        onAction = onAction,
-                        calculatorOffsetKHz = uiState.calculatorOffsetKHz
+                        onAction = onAction
                     )
                     RadarPage.Sstv -> SstvPage(
                         sstv = uiState.sstv,

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

@@ -63,8 +63,7 @@ data class RadarState(
     val moonPosition: CelestialComputer.MoonPosition? = null,
     val transceivers: TransceiverSubState = TransceiverSubState(),
     val radioControl: RadioControlSubState = RadioControlSubState(),
-    val sstv: SstvSubState = SstvSubState(),
-    val calculatorOffsetKHz: String = ""
+    val sstv: SstvSubState = SstvSubState()
 )
 
 enum class SstvStatus { Idle, Recording }
@@ -98,7 +97,4 @@ sealed interface RadarAction {
     data object SstvReset : RadarAction
     data class SstvSelectMode(val modeName: String) : RadarAction
     data class SstvPermissionResult(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

@@ -260,17 +260,7 @@ class RadarViewModel(
                 // Compute toggle state before the update so we don't read post-update value
                 val isTogglingOff = _uiState.value.transceivers.selectedUuid == action.uuid
                 val newUuid = if (isTogglingOff) null else action.uuid
-                // Load the saved offset for the newly selected satellite
-                val offsetKHz = if (!isTogglingOff) {
-                    transponders.find { it.uuid == action.uuid }
-                        ?.catnum?.let { settingsRepo.getSatelliteOffset(it) } ?: ""
-                } else ""
-                _uiState.update {
-                    it.copy(
-                        transceivers = it.transceivers.copy(selectedUuid = newUuid),
-                        calculatorOffsetKHz = offsetKHz
-                    )
-                }
+                _uiState.update { it.copy(transceivers = it.transceivers.copy(selectedUuid = newUuid)) }
                 // Only update the tracking service when selecting a different transponder to
                 // avoid resetting a user-adjusted TX base on re-expand
                 if (!isTogglingOff) {
@@ -319,15 +309,6 @@ class RadarViewModel(
                 sstvDecoder?.clearPixels()
                 _uiState.update { it.copy(sstv = it.sstv.copy(currentFrame = null)) }
             }
-            is RadarAction.ChangeCalculatorOffset -> {
-                val catnum = _uiState.value.transceivers.selectedUuid?.let { uuid ->
-                    transponders.find { it.uuid == uuid }?.catnum
-                }
-                if (catnum != null) {
-                    settingsRepo.setSatelliteOffset(catnum, action.offsetKHz)
-                }
-                _uiState.update { it.copy(calculatorOffsetKHz = action.offsetKHz) }
-            }
         }
     }
 

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

@@ -128,7 +128,6 @@ fun CalculatorPage(
     selectedUuid: String?,
     orbitalPos: OrbitalPos?,
     onAction: (RadarAction) -> Unit,
-    calculatorOffsetKHz: String = "",
     modifier: Modifier = Modifier
 ) {
     val calculatorTransceivers = remember(transceivers) {
@@ -181,8 +180,6 @@ fun CalculatorPage(
             DopplerFrequencyCalculator(
                 transponder = selectedTransceiver,
                 orbitalPos = orbitalPos,
-                offsetKHz = calculatorOffsetKHz,
-                onOffsetChange = { onAction(RadarAction.ChangeCalculatorOffset(it)) },
                 modifier = Modifier.fillMaxWidth()
             )
         }
@@ -524,8 +521,6 @@ private enum class EditedField { TX, PASSBAND, RX }
 private fun DopplerFrequencyCalculator(
     transponder: SatRadio,
     orbitalPos: OrbitalPos?,
-    offsetKHz: String = "",
-    onOffsetChange: (String) -> Unit = {},
     modifier: Modifier = Modifier
 ) {
     if (orbitalPos == null || !DopplerFrequencyCalculator.isLinearTransponder(transponder)) return
@@ -534,6 +529,7 @@ private fun DopplerFrequencyCalculator(
     var txFrequencyHz by remember { mutableStateOf(0L) }
     var rxFrequencyHz by remember { mutableStateOf(0L) }
     var passbandPosition by remember { mutableStateOf(0.5f) }
+    var offsetKHz by remember { mutableStateOf("") }
     var stepSizeKHz by remember { mutableIntStateOf(1) }
 
     val offsetHz = offsetKHz.toDoubleOrNull()?.let { it * 1000 }?.toLong() ?: 0L
@@ -716,7 +712,7 @@ private fun DopplerFrequencyCalculator(
                 ) {
                     BasicTextField(
                         value = offsetKHz,
-                        onValueChange = onOffsetChange,
+                        onValueChange = { offsetKHz = it },
                         singleLine = true,
                         textStyle = TextStyle(
                             fontSize = 16.sp,