KI-AGENT: Kalender, Terminbearbeitung und Dateivorschau verbessern

mobile/app/project/[id].tsx

@@ -15,7 +15,6 @@ import {
 import { router, useLocalSearchParams } from 'expo-router';
 import * as DocumentPicker from 'expo-document-picker';
 import * as ImagePicker from 'expo-image-picker';
-import * as WebBrowser from 'expo-web-browser';
 
 import { EventCreateModal } from '@/components/event-create-modal';
 import { HistorySection } from '@/components/history-section';
@@ -34,7 +33,7 @@ import {
   updateTask,
 } from '@/src/lib/api';
 import { useAuth } from '@/src/providers/auth-provider';
-import { getOpenableFileUrl } from '@/src/lib/file-opening';
+import { openAuthenticatedFile } from '@/src/lib/file-opening';
 
 const PRIMARY = '#69c350';
 const TASK_STATUS_ORDER: TaskStatus[] = ['Offen', 'In Bearbeitung', 'Abgeschlossen'];
@@ -193,13 +192,13 @@ export default function ProjectDetailScreen() {
   }
 
   async function onOpenFile(file: ProjectFile) {
-    if (!file.url) return;
-    await WebBrowser.openBrowserAsync(getOpenableFileUrl(file.url), {
-      presentationStyle: WebBrowser.WebBrowserPresentationStyle.FORM_SHEET,
-      controlsColor: PRIMARY,
-      showTitle: true,
-      enableDefaultShareMenuItem: true,
-    });
+    if (!token || !file.url) return;
+    setError(null);
+    try {
+      await openAuthenticatedFile(file, token);
+    } catch (err) {
+      setError(err instanceof Error ? err.message : 'Das Dokument konnte nicht geöffnet werden.');
+    }
   }
 
   async function onCompleteTask(task: Task) {