refactor: enhance localization support in chat and voice input features

- Integrated localization for various dialog messages and UI elements in the chat and voice input components.
- Updated the confirmation dialog to utilize localized strings for delete messages, improving user experience across different languages.
- Enhanced voice input sheet to reflect localized text for status updates, action buttons, and prompts, ensuring consistency in user interactions.
- Improved the file attachment widget to display the attachment label in a localized manner, enhancing accessibility for users in different regions.
- Streamlined localization management by centralizing string retrieval, promoting maintainability and clarity in the codebase.

lib/l10n/app_localizations_de.dart

@@ -405,12 +405,45 @@ class AppLocalizationsDe extends AppLocalizations {
   @override
   String get addAttachment => 'Anhang hinzufügen';
 
+  @override
+  String get attachmentLabel => 'Anhang';
+
   @override
   String get tools => 'Werkzeuge';
 
   @override
   String get voiceInput => 'Spracheingabe';
 
+  @override
+  String get voice => 'Sprache';
+
+  @override
+  String get voiceStatusListening => 'Hört zu…';
+
+  @override
+  String get voiceStatusRecording => 'Nimmt auf…';
+
+  @override
+  String get voiceHoldToTalk => 'Zum Sprechen halten';
+
+  @override
+  String get voiceAutoSend => 'Automatisch senden';
+
+  @override
+  String get voiceTranscript => 'Transkript';
+
+  @override
+  String get voicePromptSpeakNow => 'Jetzt sprechen…';
+
+  @override
+  String get voicePromptTapStart => 'Tippe auf \"Starten\", um zu beginnen';
+
+  @override
+  String get voiceActionStop => 'Stopp';
+
+  @override
+  String get voiceActionStart => 'Starten';
+
   @override
   String get messageInputLabel => 'Nachrichteneingabe';
 
@@ -426,6 +459,9 @@ class AppLocalizationsDe extends AppLocalizations {
   @override
   String get send => 'Senden';
 
+  @override
+  String get codeCopiedToClipboard => 'Code in die Zwischenablage kopiert.';
+
   @override
   String get sendMessage => 'Nachricht senden';
 
@@ -829,6 +865,16 @@ class AppLocalizationsDe extends AppLocalizations {
   String get quickActionsDescription =>
       'Wähle bis zu zwei Schnellzugriffe, die neben dem Eingabefeld angepinnt werden';
 
+  @override
+  String get chatSettings => 'Chat';
+
+  @override
+  String get sendOnEnter => 'Mit Enter senden';
+
+  @override
+  String get sendOnEnterDescription =>
+      'Enter sendet (Soft-Tastatur). Cmd/Ctrl+Enter ebenfalls verfügbar';
+
   @override
   String get display => 'Anzeige';