chore: bootstrap flutter reader app skeleton

lib/core/storage/local_store.dart

@@ -0,0 +1,31 @@
+import 'package:shared_preferences/shared_preferences.dart';
+
+class LocalStore {
+  static const _kFontSize = 'reader_font_size';
+  static const _kLineHeight = 'reader_line_height';
+  static const _kLetterSpacing = 'reader_letter_spacing';
+  static const _kFontFamily = 'reader_font_family';
+
+  Future<void> saveReadingSettings({
+    required double fontSize,
+    required double lineHeight,
+    required double letterSpacing,
+    required String fontFamily,
+  }) async {
+    final prefs = await SharedPreferences.getInstance();
+    await prefs.setDouble(_kFontSize, fontSize);
+    await prefs.setDouble(_kLineHeight, lineHeight);
+    await prefs.setDouble(_kLetterSpacing, letterSpacing);
+    await prefs.setString(_kFontFamily, fontFamily);
+  }
+
+  Future<Map<String, dynamic>> getReadingSettings() async {
+    final prefs = await SharedPreferences.getInstance();
+    return {
+      'fontSize': prefs.getDouble(_kFontSize) ?? 18,
+      'lineHeight': prefs.getDouble(_kLineHeight) ?? 1.8,
+      'letterSpacing': prefs.getDouble(_kLetterSpacing) ?? 0,
+      'fontFamily': prefs.getString(_kFontFamily) ?? 'serif',
+    };
+  }
+}

lib/core/storage/secure_store.dart

@@ -0,0 +1,22 @@
+import 'package:flutter_secure_storage/flutter_secure_storage.dart';
+
+class SecureStore {
+  SecureStore() : _storage = const FlutterSecureStorage();
+
+  static const _kAccessToken = 'access_token';
+  static const _kRefreshToken = 'refresh_token';
+
+  final FlutterSecureStorage _storage;
+
+  Future<void> setAccessToken(String token) =>
+      _storage.write(key: _kAccessToken, value: token);
+
+  Future<String?> getAccessToken() => _storage.read(key: _kAccessToken);
+
+  Future<void> setRefreshToken(String token) =>
+      _storage.write(key: _kRefreshToken, value: token);
+
+  Future<String?> getRefreshToken() => _storage.read(key: _kRefreshToken);
+
+  Future<void> clear() => _storage.deleteAll();
+}