consolidated downloads dir, nextcloud origin, upload route and chat timestamps; added webdav path tests

lib/view/pages/settings/diagnostics_page.dart

@@ -94,7 +94,7 @@ class _DiagnosticsPageState extends State<DiagnosticsPage> {
         rows: await rows({
           'Marianum Connect': () async => MarianumConnectEndpoint.current(),
           'Nextcloud': () async =>
-              'https://${EndpointData().nextcloud().full()}',
+              EndpointData().nextcloud().origin(),
           'Notfall-Nachricht': () async =>
               settings.devToolsSettings.resolveEmergencyNoticeUrl(),
         }),

lib/view/pages/settings/sections/dev_tools_section.dart

@@ -121,8 +121,7 @@ class DevToolsSection extends StatelessWidget {
           ),
         ),
         trailing: const Icon(Icons.arrow_right),
-        onTap: () =>
-            MarianumConnectEndpointPicker.show(context, settings),
+        onTap: () => MarianumConnectEndpointPicker.show(context, settings),
       ),
       BlocBuilder<SettingsCubit, model.Settings>(
         bloc: settings,
@@ -137,8 +136,7 @@ class DevToolsSection extends StatelessWidget {
             title: const Text('Notfall-Nachrichtenquelle'),
             subtitle: Text(override.isEmpty ? 'Standardquelle' : override),
             trailing: const Icon(Icons.arrow_right),
-            onTap: () =>
-                _EmergencyNoticeUrlEditor.show(context, settings),
+            onTap: () => _EmergencyNoticeUrlEditor.show(context, settings),
           );
         },
       ),
@@ -146,9 +144,8 @@ class DevToolsSection extends StatelessWidget {
       _StorageTile(
         icon: Icons.settings_applications_outlined,
         title: 'Einstellungen',
-        describe: () async => filesize(
-          utf8.encode(jsonEncode(settings.val().toJson())).length,
-        ),
+        describe: () async =>
+            filesize(utf8.encode(jsonEncode(settings.val().toJson())).length),
         onOpen: (_) async => AppRoutes.openJsonViewer(
           context,
           settings.val().toJson(),
@@ -235,15 +232,16 @@ class DevToolsSection extends StatelessWidget {
       _StorageTile(
         icon: Icons.download_outlined,
         title: 'Downloads',
-        describe: () async =>
-            filesize(await directorySize(await _downloadsDir())),
+        describe: () async => filesize(
+          await directorySize(await DownloadManager.downloadsDirectory()),
+        ),
         clearTitle: 'Downloads löschen',
         clearContent:
             'Laufende Downloads werden abgebrochen und heruntergeladene '
             'Dateien gelöscht.',
         onClear: () async {
           DownloadManager.instance.clearAll();
-          final dir = await _downloadsDir();
+          final dir = await DownloadManager.downloadsDirectory();
           if (!dir.existsSync()) return;
           // Cancelled tasks can still be flushing into the folder, so deleting
           // it as a whole races them; whatever survives shows up in the size.
@@ -258,9 +256,6 @@ class DevToolsSection extends StatelessWidget {
       ),
     ],
   );
-
-  static Future<Directory> _downloadsDir() async =>
-      Directory('${(await getTemporaryDirectory()).path}/downloads');
 }
 
 /// Storage row: tap opens a detail view ([onOpen]), the trailing button clears