android: кнопки start/stop сервиса с сохранением состояния, ядро не воскресает при остановленном сервисе

- ConfigProvider: флаг service_enabled (DataStore), flow/getter/setter
- MainActivity: автозапуск сервиса только при service_enabled; edge-to-edge со светлыми иконками статус-бара
- SettingsScreen: секция Service (start/stop), stop/exit сохраняет состояние; NativeLib.restart гейтится по isReady чтобы ядро не запускалось без сервиса

tools/chatgui-android/app/src/main/java/com/utun/chat/MainActivity.kt

@@ -3,8 +3,10 @@ package com.utun.chat
 import android.content.Intent
 import android.os.Bundle
 import androidx.activity.ComponentActivity
+import androidx.activity.SystemBarStyle
 import androidx.activity.compose.BackHandler
 import androidx.activity.compose.setContent
+import androidx.activity.enableEdgeToEdge
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.navigationBarsPadding
@@ -31,8 +33,17 @@ class MainActivity : ComponentActivity() {
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
 
-        /* Start uTun headless service (must be from foreground Activity on API 34+) */
+        /* Edge-to-edge with dark status/navigation bar icons (light app theme) */
+        enableEdgeToEdge(
+            statusBarStyle = SystemBarStyle.light(android.graphics.Color.TRANSPARENT, android.graphics.Color.TRANSPARENT),
+            navigationBarStyle = SystemBarStyle.light(android.graphics.Color.TRANSPARENT, android.graphics.Color.TRANSPARENT)
+        )
+
+        /* Start uTun headless service (must be from foreground Activity on API 34+).
+           Only if it was running when the app last exited (remembered via DataStore). */
+        if (ChatApplication.instance.configProvider.getServiceEnabled()) {
             ContextCompat.startForegroundService(this, Intent(this, HeadlessService::class.java))
+        }
 
         setContent {
             val vm: ChatViewModel = viewModel(factory = ChatViewModel.Factory())

tools/chatgui-android/app/src/main/java/com/utun/chat/data/ConfigProvider.kt

@@ -47,6 +47,7 @@ class ConfigProvider(private val context: Context) {
     private val chatStandbyMinSleepSec = intPreferencesKey("chat_standby_min_sleep_sec")
     private val firstLaunchDone = booleanPreferencesKey("first_launch_done")
     private val connectionModeKey = stringPreferencesKey("connection_mode")
+    private val serviceEnabledKey = booleanPreferencesKey("service_enabled")
 
     private fun keysFilePath(): String {
         val dir = runBlocking { context.dataStore.data.first()[dbPath] } ?: context.filesDir.absolutePath
@@ -207,6 +208,18 @@ class ConfigProvider(private val context: Context) {
         context.dataStore.edit { prefs -> prefs[connectionModeKey] = mode }
     }
 
+    /* ── Background service enabled/disabled ── */
+
+    val serviceEnabledFlow: Flow<Boolean> = context.dataStore.data.map { it[serviceEnabledKey] ?: true }
+
+    fun getServiceEnabled(): Boolean = runBlocking {
+        context.dataStore.data.first()[serviceEnabledKey] ?: true
+    }
+
+    suspend fun setServiceEnabled(enabled: Boolean) {
+        context.dataStore.edit { prefs -> prefs[serviceEnabledKey] = enabled }
+    }
+
     /* ── Server entries ── */
 
     suspend fun detectInterfaces(saved: List<ServerEntry> = emptyList()): List<ServerEntry> {

tools/chatgui-android/app/src/main/java/com/utun/chat/ui/screens/SettingsScreen.kt

@@ -19,10 +19,14 @@ import com.utun.chat.ChatApplication
 import com.utun.chat.data.NativeLib
 import com.utun.chat.data.ServerEntry
 import com.utun.chat.data.LocalSocketState
+import com.utun.chat.headless.HeadlessService
 import com.utun.chat.viewmodel.ChatViewModel
+import android.content.Intent
+import androidx.core.content.ContextCompat
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.delay
 import kotlinx.coroutines.launch
+import kotlinx.coroutines.runBlocking
 import kotlinx.coroutines.withContext
 import java.util.UUID
 
@@ -47,7 +51,7 @@ fun SettingsScreen(vm: ChatViewModel, onBack: () -> Unit, onExit: () -> Unit = {
     val tabs = listOf("Settings", "Audio", "Storage")
 
     val handleBack = {
-        if (dirty) {
+        if (dirty && NativeLib.isReady()) {
             scope.launch(Dispatchers.IO) {
                 val path = provider.getString("db.path") ?: "utun_chat.db"
                 val port = provider.getInt("control.port")
@@ -115,6 +119,7 @@ private fun GeneralSettingsTab(vm: ChatViewModel, dirty: Boolean, onDirty: (Bool
     var connectionMode by remember { mutableStateOf("manual") }
 
     val localSocketStates by vm.localSockets.collectAsState()
+    val serviceEnabled by provider.serviceEnabledFlow.collectAsState(initial = true)
 
     LaunchedEffect(Unit) {
         nodeName = provider.getString("node.name") ?: provider.getDeviceName()
@@ -144,6 +149,7 @@ private fun GeneralSettingsTab(vm: ChatViewModel, dirty: Boolean, onDirty: (Bool
         connectionMode = mode; onDirty(true)
         scope.launch(Dispatchers.IO) {
             provider.setConnectionMode(mode)
+            if (NativeLib.isReady())
                 NativeLib.restart(provider.getString("db.path") ?: "",
                     provider.getInt("control.port"), provider.buildConfigText())
         }
@@ -360,16 +366,43 @@ private fun GeneralSettingsTab(vm: ChatViewModel, dirty: Boolean, onDirty: (Bool
         }
         Spacer(Modifier.height(16.dp))
 
+        /* ── Background service ── */
+        HorizontalDivider(Modifier.padding(vertical = 8.dp))
+        Text("Service", style = MaterialTheme.typography.titleMedium)
+        Row(verticalAlignment = Alignment.CenterVertically, horizontalArrangement = Arrangement.spacedBy(8.dp)) {
+            Text(if (serviceEnabled) "Running" else "Stopped", modifier = Modifier.weight(1f),
+                color = if (serviceEnabled) Color(0xFF27AE60) else MaterialTheme.colorScheme.error,
+                style = MaterialTheme.typography.bodyMedium)
+            Button(onClick = {
+                runBlocking { provider.setServiceEnabled(true) }
+                ContextCompat.startForegroundService(ChatApplication.instance,
+                    Intent(ChatApplication.instance, HeadlessService::class.java))
+            }, enabled = !serviceEnabled) { Text("Start service") }
+            Button(onClick = {
+                runBlocking { provider.setServiceEnabled(false) }
+                ChatApplication.instance.stopService(Intent(ChatApplication.instance, HeadlessService::class.java))
+            }, enabled = serviceEnabled,
+                colors = ButtonDefaults.buttonColors(containerColor = MaterialTheme.colorScheme.error)) { Text("Stop service") }
+        }
+
+        HorizontalDivider(Modifier.padding(vertical = 8.dp))
+
         Button(onClick = {
             scope.launch(Dispatchers.IO) {
+                if (NativeLib.isReady()) {
                     val path = provider.getString("db.path") ?: ""; val port = provider.getInt("control.port")
                     NativeLib.restart(path, port, provider.buildConfigText())
                 }
+            }
         }, modifier = Modifier.fillMaxWidth(), colors = ButtonDefaults.buttonColors(containerColor = MaterialTheme.colorScheme.secondary)) {
             Icon(Icons.Default.Refresh, null, modifier = Modifier.size(18.dp)); Spacer(Modifier.width(8.dp)); Text("Restart instance")
         }
         Spacer(Modifier.height(8.dp))
-        Button(onClick = { NativeLib.stop(); onExit() }, modifier = Modifier.fillMaxWidth(),
+        Button(onClick = {
+            runBlocking { provider.setServiceEnabled(false) }
+            ChatApplication.instance.stopService(Intent(ChatApplication.instance, HeadlessService::class.java))
+            onExit()
+        }, modifier = Modifier.fillMaxWidth(),
             colors = ButtonDefaults.buttonColors(containerColor = MaterialTheme.colorScheme.error)) {
             Icon(Icons.Default.PowerSettingsNew, null, modifier = Modifier.size(18.dp)); Spacer(Modifier.width(8.dp)); Text("Stop All & Exit")
         }
@@ -389,9 +422,13 @@ private fun GeneralSettingsTab(vm: ChatViewModel, dirty: Boolean, onDirty: (Bool
         confirmButton = { Button(onClick = {
             showClearDb = false; clearingDb = true
             scope.launch(Dispatchers.IO) {
-                vm.clearState(); NativeLib.stop(); NativeLib.clearDatabase()
+                vm.clearState()
+                val wasRunning = NativeLib.isReady()
+                NativeLib.stop(); NativeLib.clearDatabase()
+                if (wasRunning) {
                     val path = provider.getString("db.path") ?: ""; val port = provider.getInt("control.port")
                     NativeLib.restart(path, port, provider.buildConfigText())
+                }
                 withContext(Dispatchers.Main) { clearingDb = false }
             }
         }, enabled = !clearingDb, colors = ButtonDefaults.buttonColors(containerColor = MaterialTheme.colorScheme.error)) { Text("Delete All") } },