share weekKey extension and log splash precache failures

lib/extensions/date_time.dart

@@ -64,6 +64,9 @@ extension DateTimeFormatting on DateTime {
 
   String formatRelative() => Jiffy.parseFromDateTime(this).fromNow();
 
+  /// Compact `yyyyMMdd` key, e.g. to identify a week-start in timetable caches.
+  String weekKey() => Jiffy.parseFromDateTime(this).format(pattern: 'yyyyMMdd');
+
   String timeRangeTo(DateTime end) => '${formatHm()} - ${end.formatHm()}';
 
   String formatDateRelativeShort({DateTime? now}) {

lib/state/app/modules/foreign_timetable/bloc/foreign_timetable_bloc.dart

@@ -1,7 +1,5 @@
 import 'dart:developer';
 
-import 'package:intl/intl.dart';
-
 import '../../../../../api/marianumconnect/queries/timetable_get_element_week/timetable_element_type.dart';
 import '../../../../../api/marianumconnect/queries/timetable_get_week/timetable_get_week_response.dart';
 import '../../../../../extensions/date_time.dart';
@@ -24,7 +22,6 @@ class ForeignTimetableBloc
           TimetableState,
           ForeignTimetableRepository
         > {
-  static final DateFormat _weekKeyFormat = DateFormat('yyyyMMdd');
 
   final TimetableElementType type;
   // Named `elementId` rather than `id` to avoid shadowing HydratedMixin's
@@ -183,7 +180,7 @@ class ForeignTimetableBloc
   }
 
   void _writeWeekToCache(DateTime weekStart, TimetableGetWeekResponse week) {
-    final key = _weekKeyFormat.format(weekStart);
+    final key = weekStart.weekKey();
     add(
       Emit((s) {
         final updated = Map<String, TimetableGetWeekResponse>.of(s.weekCache);

lib/state/app/modules/timetable/bloc/timetable_bloc.dart

@@ -1,7 +1,5 @@
 import 'dart:developer';
 
-import 'package:intl/intl.dart';
-
 import '../../../../../api/marianumconnect/queries/timetable_custom_events/custom_events_migration.dart';
 import '../../../../../api/marianumconnect/queries/timetable_get_week/timetable_get_week_response.dart';
 import '../../../../../api/mhsl/custom_timetable_event/custom_timetable_event.dart';
@@ -19,8 +17,6 @@ class TimetableBloc
           TimetableState,
           TimetableRepository
         > {
-  static final DateFormat _weekKeyFormat = DateFormat('yyyyMMdd');
-
   DateTime _lastWeekRequestStart = DateTime.fromMillisecondsSinceEpoch(0);
 
   /// Set by [retry] to force the next [gatherData] to bypass cache freshness
@@ -247,7 +243,7 @@ class TimetableBloc
   }
 
   void _writeWeekToCache(DateTime weekStart, TimetableGetWeekResponse week) {
-    final key = _weekKeyFormat.format(weekStart);
+    final key = weekStart.weekKey();
     add(
       Emit((s) {
         final updated = Map<String, TimetableGetWeekResponse>.of(s.weekCache);

lib/view/login/post_login_splash.dart

@@ -19,7 +19,11 @@ class PostLoginSplash extends StatefulWidget {
     try {
       _darkComposition ??= await AssetLottie(_darkAsset).load();
       _lightComposition ??= await AssetLottie(_lightAsset).load();
-    } catch (_) {}
+    } catch (e) {
+      // Precache is a best-effort warm-up; the splash falls back to loading the
+      // composition on demand. Log so a broken asset is at least diagnosable.
+      debugPrint('PostLoginSplash.precache failed: $e');
+    }
   }
 
   final VoidCallback onComplete;

test/extensions/date_time_test.dart

@@ -115,6 +115,11 @@ void main() {
       final end = dt.add(const Duration(minutes: 45));
       expect(dt.timeRangeTo(end), '09:07 - 09:52');
     });
+
+    test('weekKey renders a zero-padded yyyyMMdd key', () {
+      expect(dt.weekKey(), '20260508');
+      expect(DateTime(2026, 12, 31).weekKey(), '20261231');
+    });
   });
 
   group('formatDateRelativeShort', () {