feat: Add Spanish, Dutch, Russian, and Chinese languages

Adds support for Spanish, Dutch, Russian, and Chinese to the language selection menu. This includes adding the necessary translation strings and updating the app customization page to display these new language options.

lib/l10n/app_de.arb

@@ -214,6 +214,10 @@
   "deutsch": "Deutsch",
   "francais": "Französisch",
   "italiano": "Italienisch",
+  "espanol": "Spanisch",
+  "nederlands": "Niederländisch",
+  "russian": "Russisch",
+  "chinese": "Chinesisch",
   "deleteMessagesTitle": "Nachrichten löschen",
   "deleteMessagesMessage": "{count} Nachrichten löschen?",
   "@deleteMessagesMessage": {

lib/l10n/app_en.arb

@@ -467,6 +467,14 @@
   "@francais": {"description": "Language name: French."},
   "italiano": "Italiano",
   "@italiano": {"description": "Language name: Italian."},
+  "espanol": "Español",
+  "@espanol": {"description": "Language name: Spanish."},
+  "nederlands": "Nederlands",
+  "@nederlands": {"description": "Language name: Dutch."},
+  "russian": "Русский",
+  "@russian": {"description": "Language name: Russian."},
+  "chinese": "中文",
+  "@chinese": {"description": "Language name: Chinese."},
   "deleteMessagesTitle": "Delete Messages",
   "@deleteMessagesTitle": {"description": "Dialog title asking to confirm deletion of messages."},
   "deleteMessagesMessage": "Delete {count} messages?",

lib/l10n/app_es.arb

@@ -211,6 +211,10 @@
   "deutsch": "Deutsch",
   "francais": "Français",
   "italiano": "Italiano",
+  "espanol": "Español",
+  "nederlands": "Nederlands",
+  "russian": "Русский",
+  "chinese": "中文",
   "deleteMessagesTitle": "Eliminar mensajes",
   "deleteMessagesMessage": "¿Eliminar {count} mensajes?",
   "@deleteMessagesMessage": {

lib/l10n/app_fr.arb

@@ -214,6 +214,10 @@
   "deutsch": "Allemand",
   "francais": "Français",
   "italiano": "Italien",
+  "espanol": "Espagnol",
+  "nederlands": "Néerlandais",
+  "russian": "Russe",
+  "chinese": "Chinois",
   "deleteMessagesTitle": "Supprimer les messages",
   "deleteMessagesMessage": "Supprimer {count} messages ?",
   "@deleteMessagesMessage": {

lib/l10n/app_it.arb

@@ -214,6 +214,10 @@
   "deutsch": "Tedesco",
   "francais": "Francese",
   "italiano": "Italiano",
+  "espanol": "Spagnolo",
+  "nederlands": "Olandese",
+  "russian": "Russo",
+  "chinese": "Cinese",
   "deleteMessagesTitle": "Elimina messaggi",
   "deleteMessagesMessage": "Eliminare {count} messaggi?",
   "@deleteMessagesMessage": {

lib/l10n/app_localizations.dart

@@ -1286,6 +1286,30 @@ abstract class AppLocalizations {
   /// **'Italiano'**
   String get italiano;
 
+  /// Language name: Spanish.
+  ///
+  /// In en, this message translates to:
+  /// **'Español'**
+  String get espanol;
+
+  /// Language name: Dutch.
+  ///
+  /// In en, this message translates to:
+  /// **'Nederlands'**
+  String get nederlands;
+
+  /// Language name: Russian.
+  ///
+  /// In en, this message translates to:
+  /// **'Русский'**
+  String get russian;
+
+  /// Language name: Chinese.
+  ///
+  /// In en, this message translates to:
+  /// **'中文'**
+  String get chinese;
+
   /// Dialog title asking to confirm deletion of messages.
   ///
   /// In en, this message translates to:

lib/l10n/app_localizations_de.dart

@@ -650,6 +650,18 @@ class AppLocalizationsDe extends AppLocalizations {
   @override
   String get italiano => 'Italienisch';
 
+  @override
+  String get espanol => 'Spanisch';
+
+  @override
+  String get nederlands => 'Niederländisch';
+
+  @override
+  String get russian => 'Russisch';
+
+  @override
+  String get chinese => 'Chinesisch';
+
   @override
   String get deleteMessagesTitle => 'Nachrichten löschen';
 

lib/l10n/app_localizations_en.dart

@@ -645,6 +645,18 @@ class AppLocalizationsEn extends AppLocalizations {
   @override
   String get italiano => 'Italiano';
 
+  @override
+  String get espanol => 'Español';
+
+  @override
+  String get nederlands => 'Nederlands';
+
+  @override
+  String get russian => 'Русский';
+
+  @override
+  String get chinese => '中文';
+
   @override
   String get deleteMessagesTitle => 'Delete Messages';
 

lib/l10n/app_localizations_fr.dart

@@ -655,6 +655,18 @@ class AppLocalizationsFr extends AppLocalizations {
   @override
   String get italiano => 'Italien';
 
+  @override
+  String get espanol => 'Espagnol';
+
+  @override
+  String get nederlands => 'Néerlandais';
+
+  @override
+  String get russian => 'Russe';
+
+  @override
+  String get chinese => 'Chinois';
+
   @override
   String get deleteMessagesTitle => 'Supprimer les messages';
 

lib/l10n/app_localizations_it.dart

@@ -647,6 +647,18 @@ class AppLocalizationsIt extends AppLocalizations {
   @override
   String get italiano => 'Italiano';
 
+  @override
+  String get espanol => 'Spagnolo';
+
+  @override
+  String get nederlands => 'Olandese';
+
+  @override
+  String get russian => 'Russo';
+
+  @override
+  String get chinese => 'Cinese';
+
   @override
   String get deleteMessagesTitle => 'Elimina messaggi';
 

lib/l10n/app_nl.arb

@@ -211,6 +211,10 @@
   "deutsch": "Deutsch",
   "francais": "Français",
   "italiano": "Italiano",
+  "espanol": "Español",
+  "nederlands": "Nederlands",
+  "russian": "Русский",
+  "chinese": "中文",
   "deleteMessagesTitle": "Berichten verwijderen",
   "deleteMessagesMessage": "{count} berichten verwijderen?",
   "@deleteMessagesMessage": {

lib/l10n/app_ru.arb

@@ -211,6 +211,10 @@
   "deutsch": "Deutsch",
   "francais": "Français",
   "italiano": "Italiano",
+  "espanol": "Español",
+  "nederlands": "Nederlands",
+  "russian": "Русский",
+  "chinese": "中文",
   "deleteMessagesTitle": "Удалить сообщения",
   "deleteMessagesMessage": "Удалить {count, plural, one{{count} сообщение} few{{count} сообщения} other{{count} сообщений}}?",
   "@deleteMessagesMessage": {

lib/l10n/app_zh.arb

@@ -211,6 +211,10 @@
   "deutsch": "Deutsch",
   "francais": "Français",
   "italiano": "Italiano",
+  "espanol": "Español",
+  "nederlands": "Nederlands",
+  "russian": "Русский",
+  "chinese": "中文",
   "deleteMessagesTitle": "删除消息",
   "deleteMessagesMessage": "删除 {count} 条消息？",
   "@deleteMessagesMessage": {