✨ Edit alert configuration

lib/controllers/alert.dart

@@ -0,0 +1,38 @@
+import 'dart:convert';
+
+import 'package:dietary_guard/models/alert_configuration.dart';
+import 'package:get/get.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+class AlertController extends GetxController {
+  List<AlertConfiguration> configuration = List.empty();
+
+  late final SharedPreferences _prefs;
+
+  @override
+  void onInit() async {
+    _prefs = await SharedPreferences.getInstance();
+    loadAlertConfiguration();
+    super.onInit();
+  }
+
+  void loadAlertConfiguration() {
+    final raw = _prefs.getString("alert_configuration");
+    if (raw == null) return;
+    configuration = List<AlertConfiguration>.from(jsonDecode(raw).map(
+      (x) => AlertConfiguration.fromJson(x),
+    ));
+  }
+
+  Future<void> setAlertConfiguration(List<AlertConfiguration> value) async {
+    await _prefs.setString(
+      "alert_configuration",
+      jsonEncode(value.map((x) => x.toJson()).toList()),
+    );
+    loadAlertConfiguration();
+  }
+
+  void clearAlertConfiguration() {
+    _prefs.remove("alert_configuration");
+  }
+}