feat: erweiterte Chat-Funktionalität, UI-Verbesserungen und Lokalisierungsupdates

- Chat: Nachrichten-Status (read/unread), WebSocket-Verbesserungen
- App: Login-Optimierung, Job-Übersicht verbessert, neue Übersetzungen
- Backend: Dialog-Styling, Invoice-Generator, Job-Verwaltung erweitert
- Mehrsprachigkeit: Neue Übersetzungen für DE, EN, ES, ET, FR, LT, LV, PL, RU, TR

app/lib/task_view.dart

@@ -6,6 +6,7 @@ import 'package:image/image.dart' as img;
 import 'package:flutter/material.dart';
 import 'package:flutter/foundation.dart';
 import 'l10n/app_localizations.dart';
+import 'l10n/localization_helpers.dart';
 import 'models/job.dart';
 import 'models/task.dart';
 import 'models/tasks/confirmation_task.dart';
@@ -721,8 +722,14 @@ class _TaskViewState extends State<TaskView> {
       decoration: isCompleted ? TextDecoration.lineThrough : null,
     );
 
-    final displayName = task.displayName;
-    final description = task.description;
+    final displayName =
+        task.displayName != null
+            ? localizeKnownText(context, task.displayName!)
+            : null;
+    final description =
+        task.description != null
+            ? localizeKnownText(context, task.description!)
+            : null;
 
     if (displayName?.isNotEmpty == true) {
       return Column(
@@ -785,12 +792,10 @@ class _TaskViewState extends State<TaskView> {
       if (station.stationOrder == stationOrder) {
         final suffix =
             station.displayName.isNotEmpty ? station.displayName : station.city;
-        return suffix.isNotEmpty
-            ? 'Station ${stationOrder + 1}: $suffix'
-            : 'Station ${stationOrder + 1}';
+        return localizedStationLabel(context, stationOrder + 1, suffix: suffix);
       }
     }
 
-    return 'Station ${stationOrder + 1}';
+    return AppLocalizations.of(context).stationNumber(stationOrder + 1);
   }
 }