fixed possible lockups on app start

test/storage/in_memory_storage_test.dart

@@ -0,0 +1,21 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:marianum_mobile/storage/hydrated_storage_bootstrap.dart';
+
+void main() {
+  test('InMemoryStorage round-trips, deletes and clears', () async {
+    final storage = InMemoryStorage();
+    expect(storage.read('a'), isNull);
+
+    await storage.write('a', {'x': 1});
+    await storage.write('b', 'two');
+    expect(storage.read('a'), {'x': 1});
+    expect(storage.read('b'), 'two');
+
+    await storage.delete('a');
+    expect(storage.read('a'), isNull);
+    expect(storage.read('b'), 'two');
+
+    await storage.clear();
+    expect(storage.read('b'), isNull);
+  });
+}

test/utils/exponential_backoff_test.dart

@@ -0,0 +1,35 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:marianum_mobile/utils/exponential_backoff.dart';
+
+void main() {
+  group('exponentialBackoff', () {
+    test('doubles per attempt starting at base', () {
+      expect(exponentialBackoff(1), const Duration(milliseconds: 500));
+      expect(exponentialBackoff(2), const Duration(seconds: 1));
+      expect(exponentialBackoff(3), const Duration(seconds: 2));
+      expect(exponentialBackoff(4), const Duration(seconds: 4));
+    });
+
+    test('caps at max', () {
+      expect(exponentialBackoff(5), const Duration(seconds: 5));
+      expect(exponentialBackoff(40), const Duration(seconds: 5));
+      expect(exponentialBackoff(1000), const Duration(seconds: 5));
+    });
+
+    test('treats attempt 0 and negatives like the first attempt', () {
+      expect(exponentialBackoff(0), const Duration(milliseconds: 500));
+      expect(exponentialBackoff(-3), const Duration(milliseconds: 500));
+    });
+
+    test('honours custom base and max', () {
+      expect(
+        exponentialBackoff(
+          3,
+          base: const Duration(seconds: 1),
+          max: const Duration(seconds: 3),
+        ),
+        const Duration(seconds: 3),
+      );
+    });
+  });
+}