feat: artist-page scroll/search memory (android) + move APK button to bottom (web)

- Android: the artist page's main list and the "Alle anzeigen" album overlay
  (grid scroll + search query) are hoisted into the Artist/Explore ViewModels,
  so drilling into an album/artist and back keeps position + query. Covers the
  library artist and Deezer (Explore) artist screens.
- Web: the "Android App" download section now sits at the very bottom of
  Settings, below the Navidrome-Server (account) section.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

android/app/src/main/kotlin/com/novasonic/app/ui/screen/ArtistDetailScreen.kt

@@ -215,11 +215,14 @@ fun ArtistDetailScreen(
             title   = openAllAlbums ?: "",
             entries = allAlbumEntries,
             onBack  = { openAllAlbums = null },
+            gridState     = vm.allAlbumsGrid,
+            query         = vm.allAlbumsQuery.value,
+            onQueryChange = { vm.allAlbumsQuery.value = it },
         )
         return
     }
 
-    LazyColumn(Modifier.fillMaxSize()) {
+    LazyColumn(state = vm.pageListState, modifier = Modifier.fillMaxSize()) {
         // Back link
         item {
             Row(
@@ -624,8 +627,10 @@ internal fun AllAlbumsOverlay(
     title: String,
     entries: List<AllAlbumEntry>,
     onBack: () -> Unit,
+    gridState: androidx.compose.foundation.lazy.grid.LazyGridState = androidx.compose.foundation.lazy.grid.rememberLazyGridState(),
+    query: String = "",
+    onQueryChange: (String) -> Unit = {},
 ) {
-    var query by remember { mutableStateOf("") }
     val filtered = remember(query, entries) {
         if (query.isBlank()) entries
         else entries.filter { it.name.contains(query, ignoreCase = true) }
@@ -660,11 +665,11 @@ internal fun AllAlbumsOverlay(
         // Search bar
         OutlinedTextField(
             value = query,
-            onValueChange = { query = it },
+            onValueChange = onQueryChange,
             placeholder = { Text("Suchen…", color = NsOnSurface2) },
             leadingIcon  = { Icon(Icons.Default.Search, null, tint = NsOnSurface2) },
             trailingIcon = if (query.isNotEmpty()) { {
-                IconButton(onClick = { query = "" }) {
+                IconButton(onClick = { onQueryChange("") }) {
                     Icon(Icons.Default.Clear, null, tint = NsOnSurface2)
                 }
             } } else null,
@@ -684,6 +689,7 @@ internal fun AllAlbumsOverlay(
         )
 
         LazyVerticalGrid(
+            state = gridState,
             columns = GridCells.Fixed(2),
             contentPadding = PaddingValues(horizontal = 16.dp, vertical = 8.dp),
             horizontalArrangement = Arrangement.spacedBy(12.dp),

android/app/src/main/kotlin/com/novasonic/app/ui/screen/ExploreScreen.kt

@@ -145,6 +145,9 @@ fun ExploreScreen(
                     allAlbumsOpen        = state.artistAllAlbums,
                     onOpenAllAlbums      = vm::openArtistAllAlbums,
                     onCloseAllAlbums     = vm::closeArtistAllAlbums,
+                    allAlbumsGrid          = vm.allAlbumsGrid,
+                    allAlbumsQuery         = vm.allAlbumsQuery.value,
+                    onAllAlbumsQueryChange = { vm.allAlbumsQuery.value = it },
                 )
             }
         }

android/app/src/main/kotlin/com/novasonic/app/ui/screen/ItunesArtistScreen.kt

@@ -109,6 +109,9 @@ fun ItunesArtistScreen(
     allAlbumsOpen: String?,
     onOpenAllAlbums: (String) -> Unit,
     onCloseAllAlbums: () -> Unit,
+    allAlbumsGrid: androidx.compose.foundation.lazy.grid.LazyGridState = androidx.compose.foundation.lazy.grid.rememberLazyGridState(),
+    allAlbumsQuery: String = "",
+    onAllAlbumsQueryChange: (String) -> Unit = {},
 ) {
     val artist = artistState.artist
     val cats   = if (!artistState.isLoading)
@@ -144,6 +147,9 @@ fun ItunesArtistScreen(
             title   = allAlbumsOpen,
             entries = allAlbumEntries,
             onBack  = onCloseAllAlbums,
+            gridState     = allAlbumsGrid,
+            query         = allAlbumsQuery,
+            onQueryChange = onAllAlbumsQueryChange,
         )
         return
     }

android/app/src/main/kotlin/com/novasonic/app/viewmodel/ArtistViewModel.kt

@@ -70,6 +70,12 @@ class ArtistViewModel(app: Application, savedState: SavedStateHandle) : AndroidV
     private val _state = MutableStateFlow(ArtistUiState())
     val state: StateFlow<ArtistUiState> = _state
 
+    // Scroll of the artist page + the "alle anzeigen" overlay, hoisted so tapping an album/artist and
+    // coming back returns you to the same spot (the artist route entry, hence this VM, is retained).
+    val pageListState    = androidx.compose.foundation.lazy.LazyListState()
+    val allAlbumsGrid    = androidx.compose.foundation.lazy.grid.LazyGridState()
+    val allAlbumsQuery   = androidx.compose.runtime.mutableStateOf("")
+
     init {
         if (artistId.isNullOrBlank()) {
             _state.value = ArtistUiState(isLoading = false, error = "Keine Künstler-ID übergeben")

android/app/src/main/kotlin/com/novasonic/app/viewmodel/ExploreViewModel.kt

@@ -79,6 +79,10 @@ class ExploreViewModel(app: Application) : AndroidViewModel(app) {
 
     // Global-search results scroll — hoisted so it survives an album/artist drill-in and back.
     val searchListState = LazyListState()
+    // "Alle anzeigen" overlay (Deezer artist albums): scroll + search query, hoisted so an album
+    // drill-in and back keeps both (the overlay itself leaves composition on drill-in).
+    val allAlbumsGrid  = androidx.compose.foundation.lazy.grid.LazyGridState()
+    val allAlbumsQuery = androidx.compose.runtime.mutableStateOf("")
 
     private var searchJob: Job? = null