feat: implement PlatformBackHandler for back navigation support across platforms

composeApp/src/androidMain/kotlin/com/nuvio/app/core/ui/PlatformBackHandler.android.kt

@@ -0,0 +1,12 @@
+package com.nuvio.app.core.ui
+
+import androidx.activity.compose.BackHandler
+import androidx.compose.runtime.Composable
+
+@Composable
+actual fun PlatformBackHandler(
+    enabled: Boolean,
+    onBack: () -> Unit,
+) {
+    BackHandler(enabled = enabled, onBack = onBack)
+}

composeApp/src/commonMain/kotlin/com/nuvio/app/core/ui/PlatformBackHandler.kt

@@ -0,0 +1,9 @@
+package com.nuvio.app.core.ui
+
+import androidx.compose.runtime.Composable
+
+@Composable
+expect fun PlatformBackHandler(
+    enabled: Boolean,
+    onBack: () -> Unit,
+)

composeApp/src/commonMain/kotlin/com/nuvio/app/features/settings/SettingsScreen.kt

@@ -33,6 +33,7 @@ import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.max
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import com.nuvio.app.core.ui.PlatformBackHandler
 import com.nuvio.app.core.ui.NuvioScreen
 import com.nuvio.app.core.ui.NuvioScreenHeader
 import com.nuvio.app.features.addons.AddonRepository
@@ -61,6 +62,12 @@ fun SettingsScreen(
 
         var currentPage by rememberSaveable { mutableStateOf(SettingsPage.Root.name) }
         val page = remember(currentPage) { SettingsPage.valueOf(currentPage) }
+        val previousPage = page.previousPage()
+
+        PlatformBackHandler(
+            enabled = previousPage != null,
+            onBack = { previousPage?.let { currentPage = it.name } },
+        )
 
         if (maxWidth >= 768.dp) {
             TabletSettingsScreen(

composeApp/src/iosMain/kotlin/com/nuvio/app/core/ui/PlatformBackHandler.ios.kt

@@ -0,0 +1,9 @@
+package com.nuvio.app.core.ui
+
+import androidx.compose.runtime.Composable
+
+@Composable
+actual fun PlatformBackHandler(
+    enabled: Boolean,
+    onBack: () -> Unit,
+) = Unit