simplified code across the app and consolidated duplicated helpers

lib/widget/downloads/downloads_sheet.dart

@@ -2,10 +2,8 @@ import 'dart:async';
 
 import 'package:flutter/material.dart';
 
-import '../../routing/app_routes.dart';
 import '../../utils/downloads/download_job.dart';
 import '../../utils/downloads/download_manager.dart';
-import '../../utils/haptics.dart';
 import '../../view/pages/files/data/file_type_icon.dart';
 import '../centered_leading.dart';
 import '../details_bottom_sheet.dart';
@@ -90,14 +88,7 @@ class _DownloadsListState extends State<_DownloadsList> {
     // Pop the sheet first so a stale-file dialog lands on the underlying
     // screen instead of an emptied sheet.
     Navigator.of(widget.sheetContext).pop();
-    if (!ensureDownloadStillExists(widget.rootContext, job)) return;
-    Haptics.success();
-    DownloadManager.instance.markOpened(job);
-    AppRoutes.openFileViewer(
-      widget.rootContext,
-      path,
-      remoteFile: job.remoteFile,
-    );
+    openFinishedDownload(widget.rootContext, job, path);
   }
 }
 
@@ -140,8 +131,7 @@ class _DownloadRow extends StatelessWidget {
           DownloadInProgress() => IconButton(
             icon: const Icon(Icons.close),
             tooltip: 'Abbrechen',
-            onPressed: () =>
-                unawaited(DownloadManager.instance.cancel(job)),
+            onPressed: () => unawaited(DownloadManager.instance.cancel(job)),
           ),
           DownloadFailed() => IconButton(
             icon: const Icon(Icons.refresh),
@@ -167,7 +157,10 @@ class _DownloadRow extends StatelessWidget {
           alignment: Alignment.centerRight,
           padding: const EdgeInsets.only(right: 24),
           color: theme.colorScheme.errorContainer,
-          child: Icon(Icons.delete_outline, color: theme.colorScheme.onErrorContainer),
+          child: Icon(
+            Icons.delete_outline,
+            color: theme.colorScheme.onErrorContainer,
+          ),
         ),
         onDismissed: (_) => DownloadManager.instance.dismiss(job),
         child: tile,