fix(UI): Apply window insets on welcome screens (#2734)

app/src/main/java/com/geeksville/mesh/MainActivity.kt

@@ -22,10 +22,13 @@ import android.app.TaskStackBuilder
 import android.content.Intent
 import android.content.pm.PackageInfo
 import android.content.pm.PackageManager
+import android.graphics.Color
 import android.hardware.usb.UsbManager
 import android.net.Uri
+import android.os.Build
 import android.os.Bundle
 import android.widget.Toast
+import androidx.activity.SystemBarStyle
 import androidx.activity.compose.setContent
 import androidx.activity.enableEdgeToEdge
 import androidx.activity.result.contract.ActivityResultContracts
@@ -41,7 +44,6 @@ import androidx.compose.runtime.setValue
 import androidx.compose.ui.platform.LocalView
 import androidx.core.content.edit
 import androidx.core.net.toUri
-import androidx.core.view.WindowCompat
 import androidx.lifecycle.lifecycleScope
 import com.geeksville.mesh.android.BindFailedException
 import com.geeksville.mesh.android.GeeksvilleApplication
@@ -78,7 +80,15 @@ class MainActivity :
     private var showAppIntro by mutableStateOf(false)
 
     override fun onCreate(savedInstanceState: Bundle?) {
-        enableEdgeToEdge()
+        enableEdgeToEdge(
+            // Disable three-button navbar scrim on pre-Q devices
+            navigationBarStyle = SystemBarStyle.auto(Color.TRANSPARENT, Color.TRANSPARENT),
+        )
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
+            // Disable three-button navbar scrim
+            window.setNavigationBarContrastEnforced(false)
+        }
+
         super.onCreate(savedInstanceState)
         val prefs = UIViewModel.getPreferences(this)
         if (savedInstanceState == null) {
@@ -93,7 +103,6 @@ class MainActivity :
             }
         }
 
-        WindowCompat.setDecorFitsSystemWindows(window, false)
         setContent {
             val theme by model.theme.collectAsState()
             val dynamic = theme == MODE_DYNAMIC

app/src/main/java/com/geeksville/mesh/ui/intro/IntroBottomBar.kt

@@ -17,15 +17,13 @@
 
 package com.geeksville.mesh.ui.intro
 
-import androidx.compose.foundation.layout.Arrangement
-import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.PaddingValues
+import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.fillMaxWidth
-import androidx.compose.foundation.layout.padding
+import androidx.compose.material3.BottomAppBar
 import androidx.compose.material3.Button
-import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
-import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.unit.dp
 
@@ -47,17 +45,13 @@ internal fun IntroBottomBar(
     configureButtonText: String,
     showSkipButton: Boolean = true,
 ) {
-    Surface(shadowElevation = 8.dp) {
-        // Use Surface for elevation as per Material 3 guidelines
-        Row(
-            modifier = Modifier.fillMaxWidth().padding(horizontal = 16.dp, vertical = 20.dp),
-            verticalAlignment = Alignment.CenterVertically,
-            horizontalArrangement = if (showSkipButton) Arrangement.SpaceBetween else Arrangement.End,
-        ) {
-            if (showSkipButton) {
-                Button(onClick = onSkip) { Text(skipButtonText) }
-            }
-            Button(onClick = onConfigure) { Text(configureButtonText) }
+    BottomAppBar(contentPadding = PaddingValues(horizontal = 16.dp, vertical = 20.dp)) {
+        if (showSkipButton) {
+            Button(onClick = onSkip) { Text(skipButtonText) }
         }
+
+        Spacer(modifier = Modifier.fillMaxWidth().weight(1f))
+
+        Button(onClick = onConfigure) { Text(configureButtonText) }
     }
 }