feat(frontend): flossy стиль. Выбор градиент/без

lib/core/config/app_pill_gradient.dart

@@ -0,0 +1,18 @@
+import 'package:flutter/foundation.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+class AppPillGradient {
+  static const prefKey = 'app_pill_gradient';
+  static final ValueNotifier<bool> current = ValueNotifier(true);
+
+  static Future<bool> load() async {
+    final prefs = await SharedPreferences.getInstance();
+    return prefs.getBool(prefKey) ?? true;
+  }
+
+  static Future<void> save(bool value) async {
+    current.value = value;
+    final prefs = await SharedPreferences.getInstance();
+    await prefs.setBool(prefKey, value);
+  }
+}

lib/core/config/app_visual_style.dart

@@ -0,0 +1,26 @@
+import 'package:flutter/foundation.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+enum VisualStyle { materialYou, glossy }
+
+class AppVisualStyle {
+  static const prefKey = 'app_visual_style';
+  static final ValueNotifier<VisualStyle> current =
+      ValueNotifier(VisualStyle.materialYou);
+
+  static Future<VisualStyle> load() async {
+    final prefs = await SharedPreferences.getInstance();
+    return prefs.getString(prefKey) == 'glossy'
+        ? VisualStyle.glossy
+        : VisualStyle.materialYou;
+  }
+
+  static Future<void> save(VisualStyle value) async {
+    current.value = value;
+    final prefs = await SharedPreferences.getInstance();
+    await prefs.setString(
+      prefKey,
+      value == VisualStyle.glossy ? 'glossy' : 'materialYou',
+    );
+  }
+}