feat(feed_decorators): add localization extension for feed decorator types

- Create new extension on FeedDecoratorType for localized strings
- Implement randomized string selection for titles, descriptions, and CTAs
- Add support for multiple languages through AppLocalizations
- Improve maintainability and clean up UI components by centralizing string logic

Author: fulleni

lib/feed_decorators/extensions/feed_decorator_type_l10n.dart

@@ -0,0 +1,126 @@
+import 'dart:math';
+
+import 'package:core/core.dart';
+import 'package:flutter_news_app_mobile_client_full_source_code/l10n/app_localizations.dart';
+
+/// An extension on [FeedDecoratorType] to provide randomized, localized
+/// strings for decorator titles, descriptions, and calls to action.
+///
+/// This centralizes the logic for selecting from multiple string variations,
+/// making the UI components cleaner and the string management more maintainable.
+extension FeedDecoratorTypeL10n on FeedDecoratorType {
+  /// Returns a random string from a list of string-producing functions.
+  ///
+  /// This helper function is used to select a random variation of a
+  /// localized string. It takes a list of functions, each returning a string,
+  /// and executes one at random.
+  String _randomString(List<String> options) {
+    if (options.isEmpty) return '';
+    final randomIndex = Random().nextInt(options.length);
+    return options[randomIndex];
+  }
+
+  /// Gets a randomized, localized title for the decorator.
+  ///
+  /// Uses a switch statement on the decorator type to determine the correct
+  /// set of title variations from [AppLocalizations] and then selects one
+  /// randomly.
+  String getRandomTitle(AppLocalizations l10n) {
+    switch (this) {
+      case FeedDecoratorType.linkAccount:
+        return _randomString([
+          l10n.decoratorLinkAccountTitle_1,
+          l10n.decoratorLinkAccountTitle_2,
+        ]);
+      case FeedDecoratorType.upgrade:
+        return _randomString([
+          l10n.decoratorUpgradeTitle_1,
+          l10n.decoratorUpgradeTitle_2,
+        ]);
+      case FeedDecoratorType.rateApp:
+        return _randomString([
+          l10n.decoratorRateAppTitle_1,
+          l10n.decoratorRateAppTitle_2,
+        ]);
+      case FeedDecoratorType.enableNotifications:
+        return _randomString([
+          l10n.decoratorEnableNotificationsTitle_1,
+          l10n.decoratorEnableNotificationsTitle_2,
+        ]);
+      case FeedDecoratorType.suggestedTopics:
+        return _randomString([
+          l10n.decoratorSuggestedTopicsTitle_1,
+          l10n.decoratorSuggestedTopicsTitle_2,
+        ]);
+      case FeedDecoratorType.suggestedSources:
+        return _randomString([
+          l10n.decoratorSuggestedSourcesTitle_1,
+          l10n.decoratorSuggestedSourcesTitle_2,
+        ]);
+    }
+  }
+
+  /// Gets a randomized, localized description for the decorator.
+  ///
+  /// This only applies to [FeedDecoratorCategory.callToAction] decorators.
+  /// It returns an empty string for content collection types.
+  String getRandomDescription(AppLocalizations l10n) {
+    switch (this) {
+      case FeedDecoratorType.linkAccount:
+        return _randomString([
+          l10n.decoratorLinkAccountDescription_1,
+          l10n.decoratorLinkAccountDescription_2,
+        ]);
+      case FeedDecoratorType.upgrade:
+        return _randomString([
+          l10n.decoratorUpgradeDescription_1,
+          l10n.decoratorUpgradeDescription_2,
+        ]);
+      case FeedDecoratorType.rateApp:
+        return _randomString([
+          l10n.decoratorRateAppDescription_1,
+          l10n.decoratorRateAppDescription_2,
+        ]);
+      case FeedDecoratorType.enableNotifications:
+        return _randomString([
+          l10n.decoratorEnableNotificationsDescription_1,
+          l10n.decoratorEnableNotificationsDescription_2,
+        ]);
+      case FeedDecoratorType.suggestedTopics:
+      case FeedDecoratorType.suggestedSources:
+        return '';
+    }
+  }
+
+  /// Gets a randomized, localized call-to-action text for the decorator.
+  ///
+  /// This only applies to [FeedDecoratorCategory.callToAction] decorators.
+  /// It returns an empty string for content collection types.
+  String getRandomCtaText(AppLocalizations l10n) {
+    switch (this) {
+      case FeedDecoratorType.linkAccount:
+        return _randomString([
+          l10n.decoratorLinkAccountCta_1,
+          l10n.decoratorLinkAccountCta_2,
+        ]);
+      case FeedDecoratorType.upgrade:
+        return _randomString([
+          l10n.decoratorUpgradeCta_1,
+          l10n.decoratorUpgradeCta_2,
+        ]);
+      case FeedDecoratorType.rateApp:
+        return _randomString([
+          l10n.decoratorRateAppCta_1,
+          l10n.decoratorRateAppCta_2,
+        ]);
+      case FeedDecoratorType.enableNotifications:
+        return _randomString([
+          l10n.decoratorEnableNotificationsCta_1,
+          l10n.decoratorEnableNotificationsCta_2,
+        ]);
+      case FeedDecoratorType.suggestedTopics:
+      case FeedDecoratorType.suggestedSources:
+        return '';
+    }
+  }
+}