feat(gridfinder): VUCC 网格寻线实地导航 + LoTW 上传台址预填联动 + 移除地图入口

- GridGeometry 网格线/点几何 + QthConverter grid4/grid8；golden vectors 单测
- 独立定位流 ILocationRepo/LocationRepo（stop 时 removeUpdates），不自动写台址
- feature/gridfinder 模块：罗盘表盘、极坐标近距图、线上/点上精度门控（连续 3 次 ≤6.1m）
- 「设为 LoTW 上传台址」：跳证书配置页并预填当前网格（1/2/4 格），只改台站 grid 字段
- 地图页入口移除，设置页单入口；顶部间距改 ScreenColumn 结构（与设置页同构）
- 术语统一「最近网格点」（中英）

core/data/src/main/java/com/rtbishop/look4sat/core/data/injection/MainContainer.kt

@@ -17,11 +17,14 @@
  */
 package com.rtbishop.look4sat.core.data.injection
 
+import android.Manifest
 import android.bluetooth.BluetoothManager
 import android.content.Context
+import android.content.pm.PackageManager
 import android.hardware.SensorManager
 import android.hardware.display.DisplayManager
 import android.location.LocationManager
+import androidx.core.content.ContextCompat
 import androidx.room.Room
 import com.rtbishop.look4sat.core.data.database.Look4SatDb
 import com.rtbishop.look4sat.core.data.database.MIGRATION_1_2
@@ -43,6 +46,7 @@ import com.rtbishop.look4sat.core.data.repository.SensorsRepo
 import com.rtbishop.look4sat.core.data.repository.SettingsRepo
 import com.rtbishop.look4sat.core.data.repository.UpdateRepository
 import com.rtbishop.look4sat.core.data.repository.LoTWRepository
+import com.rtbishop.look4sat.core.data.repository.LocationRepo
 import com.rtbishop.look4sat.core.data.repository.WavelogRepository
 import com.rtbishop.look4sat.core.data.source.LocalSource
 import com.rtbishop.look4sat.core.data.source.RemoteSource
@@ -59,6 +63,7 @@ import com.rtbishop.look4sat.core.domain.repository.IRadioController
 import com.rtbishop.look4sat.core.domain.repository.IRadioTrackingService
 import com.rtbishop.look4sat.core.domain.repository.IReporter
 import com.rtbishop.look4sat.core.domain.repository.ILoTWRepository
+import com.rtbishop.look4sat.core.domain.repository.ILocationRepo
 import com.rtbishop.look4sat.core.domain.repository.ISatelliteRepo
 import com.rtbishop.look4sat.core.domain.repository.ISelectionRepo
 import com.rtbishop.look4sat.core.domain.repository.ISensorsRepo
@@ -107,13 +112,25 @@ class MainContainer(private val context: Context) : IMainContainer {
         val manager = context.getSystemService(Context.BLUETOOTH_SERVICE) as BluetoothManager
         RadioTrackingService(appScope, manager, satelliteRepo, settingsRepo)
     }
+    override val locationRepo: ILocationRepo by lazy {
+        val manager = context.getSystemService(Context.LOCATION_SERVICE) as LocationManager
+        LocationRepo(manager) {
+            ContextCompat.checkSelfPermission(context, Manifest.permission.ACCESS_FINE_LOCATION) ==
+                PackageManager.PERMISSION_GRANTED
+        }
+    }
 
     private val _mutualPassData = MutableStateFlow(MutualPassData())
     override val mutualPassData: StateFlow<MutualPassData> = _mutualPassData.asStateFlow()
+    private val _pendingLoTWStationGrid = MutableStateFlow<String?>(null)
+    override val pendingLoTWStationGrid: StateFlow<String?> = _pendingLoTWStationGrid.asStateFlow()
 
     override fun setMutualPassData(data: MutualPassData) {
         _mutualPassData.value = data
     }
+    override fun setPendingLoTWStationGrid(grid: String?) {
+        _pendingLoTWStationGrid.value = grid
+    }
 
     override fun provideAddToCalendar(): IAddToCalendar = AddToCalendar(context)
 

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

@@ -0,0 +1,134 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.data.repository
+
+import android.location.Location
+import android.location.LocationListener
+import android.location.LocationManager
+import androidx.core.location.LocationManagerCompat
+import com.rtbishop.look4sat.core.domain.repository.ILocationRepo
+import com.rtbishop.look4sat.core.domain.repository.LocationFix
+import com.rtbishop.look4sat.core.domain.repository.LocationState
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+
+private const val UPDATE_INTERVAL_MS = 1_000L
+private const val UPDATE_MIN_DISTANCE_M = 0f
+
+/**
+ * Live-location adapter for the field tools. Deliberately independent of
+ * [SettingsRepo]'s station position: a walk around a grid corner must not
+ * rewrite the station that every pass prediction is built on.
+ *
+ * Unlike [SettingsRepo.setStationPosition], this class always calls
+ * [LocationManager.removeUpdates] in [stopUpdates], so the listener is only
+ * alive while a screen is actually collecting fixes.
+ */
+class LocationRepo(
+    private val locationManager: LocationManager,
+    private val permissionGranted: () -> Boolean
+) : ILocationRepo, LocationListener {
+
+    private val _state = MutableStateFlow(initialState())
+    override val state: StateFlow<LocationState> = _state.asStateFlow()
+
+    private var isRegistered = false
+
+    override fun hasPermission(): Boolean = permissionGranted()
+
+    override fun startUpdates() {
+        if (isRegistered) return
+        val request = describeProvider() ?: return
+        if (!request.permissionGranted || !request.providerEnabled) return
+        try {
+            // A last-known fix is better than an empty screen while GPS warms up.
+            locationManager.getLastKnownLocation(request.provider)?.let(::publish)
+            locationManager.requestLocationUpdates(
+                request.provider, UPDATE_INTERVAL_MS, UPDATE_MIN_DISTANCE_M, this
+            )
+            isRegistered = true
+        } catch (exception: SecurityException) {
+            println("LocationRepo: no permission - $exception")
+        } catch (exception: IllegalArgumentException) {
+            println("LocationRepo: provider unavailable - $exception")
+        }
+    }
+
+    override fun stopUpdates() {
+        if (!isRegistered) return
+        isRegistered = false
+        try {
+            locationManager.removeUpdates(this)
+        } catch (exception: SecurityException) {
+            println("LocationRepo: removing updates without permission - $exception")
+        }
+    }
+
+    override fun onLocationChanged(location: Location) = publish(location)
+
+    override fun onProviderDisabled(provider: String) = refreshWaitingState()
+
+    override fun onProviderEnabled(provider: String) = refreshWaitingState()
+
+    private fun publish(location: Location) {
+        _state.value = LocationState.Fix(
+            LocationFix(
+                latitude = location.latitude,
+                longitude = location.longitude,
+                altitudeMeters = location.altitude.takeIf { location.hasAltitude() } ?: 0.0,
+                // Providers that cannot report accuracy use -1; treat that as
+                // useless rather than perfect.
+                accuracyMeters = location.accuracy.takeIf { location.hasAccuracy() } ?: Float.MAX_VALUE,
+                epochMs = location.time.takeIf { it > 0L } ?: System.currentTimeMillis()
+            )
+        )
+    }
+
+    private fun initialState(): LocationState {
+        val request = describeProvider()
+        return LocationState.Waiting(
+            permissionGranted = request?.permissionGranted ?: false,
+            providerEnabled = request?.providerEnabled ?: false
+        )
+    }
+
+    private fun refreshWaitingState() {
+        if (_state.value is LocationState.Fix) return
+        _state.value = initialState()
+    }
+
+    private fun describeProvider(): ProviderRequest? {
+        if (!permissionGranted()) {
+            return ProviderRequest(LocationManager.GPS_PROVIDER, false, false)
+        }
+        val enabled = LocationManagerCompat.isLocationEnabled(locationManager)
+        val provider = when {
+            locationManager.allProviders.contains(LocationManager.GPS_PROVIDER) -> LocationManager.GPS_PROVIDER
+            locationManager.allProviders.contains(LocationManager.NETWORK_PROVIDER) -> LocationManager.NETWORK_PROVIDER
+            else -> null
+        } ?: return null
+        return ProviderRequest(provider, true, enabled)
+    }
+
+    private data class ProviderRequest(
+        val provider: String,
+        val permissionGranted: Boolean,
+        val providerEnabled: Boolean
+    )
+}