feat(l10n): add demo ad placeholder texts for Arabic and English

- Add Arabic translations for new demo ad placeholder texts
- Introduce English texts for native, banner, and interstitial ad placeholders
- Include descriptions for full-screen ad placeholder and its text

Author: fulleni

lib/l10n/app_localizations.dart

@@ -1651,6 +1651,30 @@ abstract class AppLocalizations {
   /// In en, this message translates to:
   /// **'Unfollow'**
   String get unfollowButtonText;
+
+  /// Text displayed in the native ad placeholder in demo mode.
+  ///
+  /// In en, this message translates to:
+  /// **'NATIVE AD (DEMO)'**
+  String get demoNativeAdText;
+
+  /// Text displayed in the banner ad placeholder in demo mode.
+  ///
+  /// In en, this message translates to:
+  /// **'BANNER AD (DEMO)'**
+  String get demoBannerAdText;
+
+  /// Text displayed in the interstitial ad placeholder in demo mode.
+  ///
+  /// In en, this message translates to:
+  /// **'INTERSTITIAL AD (DEMO)'**
+  String get demoInterstitialAdText;
+
+  /// Description text for the interstitial ad placeholder in demo mode.
+  ///
+  /// In en, this message translates to:
+  /// **'This is a full-screen advertisement placeholder.'**
+  String get demoInterstitialAdDescription;
 }
 
 class _AppLocalizationsDelegate

lib/l10n/app_localizations_ar.dart

@@ -860,4 +860,17 @@ class AppLocalizationsAr extends AppLocalizations {
 
   @override
   String get unfollowButtonText => 'إلغاء المتابعة';
+
+  @override
+  String get demoNativeAdText => 'إعلان أصلي (الوضع التجريبي)';
+
+  @override
+  String get demoBannerAdText => 'إعلان بانر (الوضع التجريبي)';
+
+  @override
+  String get demoInterstitialAdText => 'إعلان بيني (الوضع التجريبي)';
+
+  @override
+  String get demoInterstitialAdDescription =>
+      'هذا عنصر نائب لإعلان بملء الشاشة.';
 }

lib/l10n/app_localizations_en.dart

@@ -863,4 +863,17 @@ class AppLocalizationsEn extends AppLocalizations {
 
   @override
   String get unfollowButtonText => 'Unfollow';
+
+  @override
+  String get demoNativeAdText => 'NATIVE AD (DEMO)';
+
+  @override
+  String get demoBannerAdText => 'BANNER AD (DEMO)';
+
+  @override
+  String get demoInterstitialAdText => 'INTERSTITIAL AD (DEMO)';
+
+  @override
+  String get demoInterstitialAdDescription =>
+      'This is a full-screen advertisement placeholder.';
 }

lib/l10n/arb/app_ar.arb

@@ -1124,5 +1124,21 @@
     "unfollowButtonText": "إلغاء المتابعة",
     "@unfollowButtonText": {
         "description": "Text for the unfollow button on suggestion items"
+    },
+    "demoNativeAdText": "إعلان أصلي (الوضع التجريبي)",
+    "@demoNativeAdText": {
+        "description": "النص المعروض في العنصر النائب للإعلان الأصلي في الوضع التجريبي."
+    },
+    "demoBannerAdText": "إعلان بانر (الوضع التجريبي)",
+    "@demoBannerAdText": {
+        "description": "النص المعروض في العنصر النائب لإعلان البانر في الوضع التجريبي."
+    },
+    "demoInterstitialAdText": "إعلان بيني (الوضع التجريبي)",
+    "@demoInterstitialAdText": {
+        "description": "النص المعروض في العنصر النائب للإعلان البيني في الوضع التجريبي."
+    },
+    "demoInterstitialAdDescription": "هذا عنصر نائب لإعلان بملء الشاشة.",
+    "@demoInterstitialAdDescription": {
+        "description": "نص الوصف للعنصر النائب للإعلان البيني في الوضع التجريبي."
     }
-}
+}

lib/l10n/arb/app_en.arb

@@ -1124,5 +1124,21 @@
     "unfollowButtonText": "Unfollow",
     "@unfollowButtonText": {
         "description": "Text for the unfollow button on suggestion items"
+    },
+    "demoNativeAdText": "NATIVE AD (DEMO)",
+    "@demoNativeAdText": {
+        "description": "Text displayed in the native ad placeholder in demo mode."
+    },
+    "demoBannerAdText": "BANNER AD (DEMO)",
+    "@demoBannerAdText": {
+        "description": "Text displayed in the banner ad placeholder in demo mode."
+    },
+    "demoInterstitialAdText": "INTERSTITIAL AD (DEMO)",
+    "@demoInterstitialAdText": {
+        "description": "Text displayed in the interstitial ad placeholder in demo mode."
+    },
+    "demoInterstitialAdDescription": "This is a full-screen advertisement placeholder.",
+    "@demoInterstitialAdDescription": {
+        "description": "Description text for the interstitial ad placeholder in demo mode."
     }
 }