feat: Add auto-sync, fix partner linking UI, update sharing settings

- Add 10-second periodic auto-sync to CycleEntriesNotifier
- Fix husband_devotional_screen: use partnerId for isConnected check, navigate to SharingSettingsScreen instead of legacy mock dialog
- Remove obsolete _showConnectDialog method and mock data import
- Update husband_settings_screen: show 'Partner Settings' with linked partner name when connected
- Add SharingSettingsScreen: Pad Supplies toggle (disabled when pad tracking off), Intimacy always enabled
- Add CORS OPTIONS handler to backend server
- Add _ensureServerRegistration for reliable partner linking
- Add copy button to Invite Partner dialog
- Dynamic base URL for web (uses window.location.hostname)

lib/models/prayer_request.dart

@@ -0,0 +1,53 @@
+import 'package:hive/hive.dart';
+import 'package:uuid/uuid.dart';
+
+part 'prayer_request.g.dart';
+
+@HiveType(typeId: 15)
+class PrayerRequest extends HiveObject {
+  @HiveField(0)
+  final String id;
+
+  @HiveField(1)
+  final String request;
+
+  @HiveField(2)
+  final bool isAnswered;
+
+  @HiveField(3)
+  final DateTime createdAt;
+
+  @HiveField(4)
+  final DateTime updatedAt;
+
+  PrayerRequest({
+    required this.id,
+    required this.request,
+    this.isAnswered = false,
+    required this.createdAt,
+    required this.updatedAt,
+  });
+
+  PrayerRequest copyWith({
+    String? request,
+    bool? isAnswered,
+    DateTime? updatedAt,
+  }) {
+    return PrayerRequest(
+      id: id,
+      request: request ?? this.request,
+      isAnswered: isAnswered ?? this.isAnswered,
+      createdAt: createdAt,
+      updatedAt: updatedAt ?? DateTime.now(),
+    );
+  }
+
+  factory PrayerRequest.create({required String request}) {
+    return PrayerRequest(
+      id: const Uuid().v4(),
+      request: request,
+      createdAt: DateTime.now(),
+      updatedAt: DateTime.now(),
+    );
+  }
+}