Add haptic feedback

lib/core/haptic/haptic_service.dart

@@ -0,0 +1,35 @@
+import 'package:flutter/services.dart';
+import 'package:hiddify/core/preferences/preferences_provider.dart';
+import 'package:riverpod_annotation/riverpod_annotation.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+part 'haptic_service.g.dart';
+
+@Riverpod(keepAlive: true)
+class HapticService extends _$HapticService {
+  @override
+  bool build() {
+    return _preferences.getBool(hapticFeedbackPrefKey) ?? true;
+  }
+
+  static const String hapticFeedbackPrefKey = "haptic_feedback";
+  SharedPreferences get _preferences =>
+      ref.read(sharedPreferencesProvider).requireValue;
+
+  Future<void> updatePreference(bool value) async {
+    state = value;
+    await _preferences.setBool(hapticFeedbackPrefKey, value);
+  }
+
+  Future<void> lightImpact() async {
+    if (state) {
+      await HapticFeedback.lightImpact();
+    }
+  }
+
+  Future<void> mediumImpact() async {
+    if (state) {
+      await HapticFeedback.mediumImpact();
+    }
+  }
+}