fix: handle missing assets gracefully

mobile/lib/domain/services/timeline.service.dart

@@ -10,6 +10,7 @@ import 'package:immich_mobile/domain/services/setting.service.dart';
 import 'package:immich_mobile/domain/utils/event_stream.dart';
 import 'package:immich_mobile/infrastructure/repositories/timeline.repository.dart';
 import 'package:immich_mobile/utils/async_mutex.dart';
+import 'package:logging/logging.dart';
 
 typedef TimelineAssetSource = Future<List<BaseAsset>> Function(
   int index,
@@ -77,6 +78,7 @@ class TimelineService {
   int _bufferOffset = 0;
   List<BaseAsset> _buffer = [];
   StreamSubscription? _bucketSubscription;
+  final _log = Logger('TimelineService');
 
   int _totalAssets = 0;
   int get totalAssets => _totalAssets;
@@ -128,10 +130,10 @@ class TimelineService {
 
   Stream<List<Bucket>> Function() get watchBuckets => _bucketSource;
 
-  Future<List<BaseAsset>> loadAssets(int index, int count) =>
+  Future<List<BaseAsset>?> loadAssets(int index, int count) =>
       _mutex.run(() => _loadAssets(index, count));
 
-  Future<List<BaseAsset>> _loadAssets(int index, int count) async {
+  Future<List<BaseAsset>?> _loadAssets(int index, int count) async {
     if (hasRange(index, count)) {
       return getAssets(index, count);
     }
@@ -169,9 +171,10 @@ class TimelineService {
       index + count <= _bufferOffset + _buffer.length &&
       index + count <= _totalAssets;
 
-  List<BaseAsset> getAssets(int index, int count) {
+  List<BaseAsset>? getAssets(int index, int count) {
     if (!hasRange(index, count)) {
-      throw RangeError('TimelineService::getAssets Index out of range');
+      _log.warning('TimelineService::getAssets Index out of range');
+      return null;
     }
     int start = index - _bufferOffset;
     return _buffer.slice(start, start + count);

mobile/lib/presentation/widgets/timeline/fixed/segment.model.dart

@@ -107,19 +107,22 @@ class _FixedSegmentRow extends ConsumerWidget {
     }
 
     if (timelineService.hasRange(assetIndex, assetCount)) {
-      return _buildAssetRow(
-        context,
-        timelineService.getAssets(assetIndex, assetCount),
-      );
+      final assets = timelineService.getAssets(assetIndex, assetCount);
+      if (assets == null) {
+        return _buildPlaceholder(context);
+      }
+
+      return _buildAssetRow(context, assets);
     }
 
-    return FutureBuilder<List<BaseAsset>>(
+    return FutureBuilder<List<BaseAsset>?>(
       future: timelineService.loadAssets(assetIndex, assetCount),
       builder: (context, snapshot) {
-        if (snapshot.connectionState != ConnectionState.done) {
+        if (snapshot.connectionState != ConnectionState.done ||
+            snapshot.data == null) {
           return _buildPlaceholder(context);
         }
-        return _buildAssetRow(context, snapshot.requireData);
+        return _buildAssetRow(context, snapshot.data!);
       },
     );
   }

mobile/lib/presentation/widgets/timeline/header.widget.dart

@@ -112,8 +112,9 @@ class _BulkSelectIconButton extends ConsumerWidget {
     List<BaseAsset> bucketAssets;
     try {
       bucketAssets = ref
-          .watch(timelineServiceProvider)
-          .getAssets(assetOffset, bucket.assetCount);
+              .watch(timelineServiceProvider)
+              .getAssets(assetOffset, bucket.assetCount) ??
+          [];
     } catch (e) {
       bucketAssets = <BaseAsset>[];
     }

mobile/lib/providers/timeline/multiselect.provider.dart

@@ -1,6 +1,5 @@
 import 'package:collection/collection.dart';
 import 'package:hooks_riverpod/hooks_riverpod.dart';
-
 import 'package:immich_mobile/domain/models/asset/base_asset.model.dart';
 import 'package:immich_mobile/domain/services/timeline.service.dart';
 import 'package:immich_mobile/providers/infrastructure/timeline.provider.dart';
@@ -130,7 +129,7 @@ class MultiSelectNotifier extends Notifier<MultiSelectState> {
     final assets = await _timelineService.loadAssets(offset, bucketCount);
     final selectedAssets = state.selectedAssets.toSet();
 
-    selectedAssets.addAll(assets);
+    selectedAssets.addAll(assets ?? []);
 
     state = state.copyWith(
       selectedAssets: selectedAssets,
@@ -141,14 +140,14 @@ class MultiSelectNotifier extends Notifier<MultiSelectState> {
     final assets = await _timelineService.loadAssets(offset, bucketCount);
     final selectedAssets = state.selectedAssets.toSet();
 
-    selectedAssets.removeAll(assets);
+    selectedAssets.removeAll(assets ?? []);
 
     state = state.copyWith(selectedAssets: selectedAssets);
   }
 
   void toggleBucketSelection(int offset, int bucketCount) async {
     final assets = await _timelineService.loadAssets(offset, bucketCount);
-    toggleBucketSelectionByAssets(assets);
+    toggleBucketSelectionByAssets(assets ?? []);
   }
 
   void toggleBucketSelectionByAssets(List<BaseAsset> bucketAssets) {