Add in-app copy/move, background downloads, and a Favorites tab

- WebDAV MOVE/COPY-backed copy/move for files and folders, with a
  destination picker (independent nav state so it doesn't disturb the
  Files tab's browsing position) and a conflict-resolution sheet
  (overwrite all / keep both / decide per item).
- Downloads now use the same foreground-service + notification approach
  as uploads, surviving app closure.
- Favorites is now its own tab (account-wide, via a WebDAV SEARCH query)
  instead of a Files-tab filter toggle, which couldn't represent
  favorited items outside the currently browsed folder correctly.
- Share sheet restyled to match the app's design language, plus a
  "share file directly" action via the OS share sheet; details sheet
  tab icons resized to match the bottom nav.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

lib/widgets/app_tab_view_builder.dart

@@ -1,6 +1,7 @@
 import 'package:flutter/material.dart';
 import '../models/app_tab.dart';
 import '../views/activity_view.dart';
+import '../views/favorites_view.dart';
 import '../views/files_view.dart';
 import '../views/photos_view.dart';
 import '../views/recent_view.dart';
@@ -16,6 +17,8 @@ Widget buildAppTabView(AppTab tab, ScrollController controller) {
       return FilesView(scrollController: controller);
     case AppTab.photos:
       return PhotosView(scrollController: controller);
+    case AppTab.favorites:
+      return FavoritesView(scrollController: controller);
     case AppTab.activity:
       return ActivityView(scrollController: controller);
     case AppTab.trash:

lib/widgets/details/details_sheet.dart

@@ -51,11 +51,24 @@ class DetailsSheet extends StatelessWidget {
       child: Column(
         children: [
           DetailsHeader(item: item),
+          // Icon size matches the bottom nav bar's own tab icons
+          // (FloatingBottomNavBar) rather than TabBar's oversized default,
+          // so a "tabs" affordance reads the same size everywhere in the
+          // app.
           const TabBar(
             tabs: [
-              Tab(icon: Icon(Icons.info_outline_rounded), text: 'Info'),
-              Tab(icon: Icon(Icons.history_rounded), text: 'Versions'),
-              Tab(icon: Icon(Icons.electric_bolt_rounded), text: 'Activity'),
+              Tab(
+                icon: Icon(Icons.info_outline_rounded, size: 22),
+                text: 'Info',
+              ),
+              Tab(
+                icon: Icon(Icons.history_rounded, size: 22),
+                text: 'Versions',
+              ),
+              Tab(
+                icon: Icon(Icons.electric_bolt_rounded, size: 22),
+                text: 'Activity',
+              ),
             ],
           ),
           Expanded(

lib/widgets/move_copy_conflict_sheet.dart

@@ -0,0 +1,172 @@
+import 'package:flutter/material.dart';
+import '../models/move_copy_result.dart';
+import 'gradual_bottom_sheet.dart';
+
+/// Shown after a Move/Copy batch comes back with `MoveCopyResult.conflicts`
+/// non-empty (an item with the same name already exists at the
+/// destination) - summarizes every conflict at once rather than prompting
+/// per item as they're hit, and lets the user resolve them all the same
+/// way (overwrite/keep both) or open a per-item breakdown. Returns the
+/// `ConflictChoice` map `ServerProvider.resolveConflicts` expects, or null
+/// if dismissed without choosing.
+class MoveCopyConflictSheet extends StatefulWidget {
+  final List<MoveCopyConflict> conflicts;
+  final ScrollController? scrollController;
+
+  const MoveCopyConflictSheet({
+    super.key,
+    required this.conflicts,
+    this.scrollController,
+  });
+
+  static Future<Map<String, ConflictChoice>?> show(
+    BuildContext context,
+    List<MoveCopyConflict> conflicts,
+  ) {
+    return showGradualBottomSheet<Map<String, ConflictChoice>>(
+      context,
+      builder: (context, scrollController) => MoveCopyConflictSheet(
+        conflicts: conflicts,
+        scrollController: scrollController,
+      ),
+    );
+  }
+
+  @override
+  State<MoveCopyConflictSheet> createState() => _MoveCopyConflictSheetState();
+}
+
+class _MoveCopyConflictSheetState extends State<MoveCopyConflictSheet> {
+  bool _decidingPerItem = false;
+  late final Map<String, ConflictChoice> _perItemChoices = {
+    for (final conflict in widget.conflicts)
+      conflict.item.id: ConflictChoice.keepBoth,
+  };
+
+  void _resolveAll(ConflictChoice choice) {
+    Navigator.pop(context, {
+      for (final conflict in widget.conflicts) conflict.item.id: choice,
+    });
+  }
+
+  void _confirmPerItem() {
+    Navigator.pop(context, _perItemChoices);
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = Theme.of(context);
+    final colorScheme = theme.colorScheme;
+    final count = widget.conflicts.length;
+
+    return ListView(
+      controller: widget.scrollController,
+      padding: const EdgeInsets.fromLTRB(20, 12, 20, 24),
+      children: [
+        Text(
+          count == 1
+              ? '1 item already exists at the destination'
+              : '$count items already exist at the destination',
+          style: theme.textTheme.titleMedium?.copyWith(
+            fontWeight: FontWeight.w700,
+          ),
+        ),
+        const SizedBox(height: 4),
+        Text(
+          'Choose how to handle the conflicts.',
+          style: theme.textTheme.bodySmall?.copyWith(
+            color: colorScheme.onSurfaceVariant,
+          ),
+        ),
+        const SizedBox(height: 16),
+        if (!_decidingPerItem) ...[
+          FilledButton(
+            onPressed: () => _resolveAll(ConflictChoice.overwrite),
+            child: const Text('Overwrite all'),
+          ),
+          const SizedBox(height: 8),
+          FilledButton.tonal(
+            onPressed: () => _resolveAll(ConflictChoice.keepBoth),
+            child: const Text('Keep both (rename)'),
+          ),
+          const SizedBox(height: 8),
+          OutlinedButton(
+            onPressed: () => setState(() => _decidingPerItem = true),
+            child: const Text('Decide per item'),
+          ),
+          const SizedBox(height: 16),
+          const Divider(),
+          const SizedBox(height: 8),
+        ],
+        for (final conflict in widget.conflicts)
+          Padding(
+            padding: const EdgeInsets.symmetric(vertical: 8),
+            child: Column(
+              crossAxisAlignment: CrossAxisAlignment.start,
+              children: [
+                Row(
+                  children: [
+                    Icon(
+                      conflict.item.isFolder
+                          ? Icons.folder_rounded
+                          : Icons.insert_drive_file_rounded,
+                      color: colorScheme.onSurfaceVariant,
+                      size: 20,
+                    ),
+                    const SizedBox(width: 10),
+                    Expanded(
+                      child: Text(
+                        conflict.item.name,
+                        maxLines: 1,
+                        overflow: TextOverflow.ellipsis,
+                        style: theme.textTheme.bodyMedium?.copyWith(
+                          fontWeight: FontWeight.w600,
+                        ),
+                      ),
+                    ),
+                  ],
+                ),
+                if (_decidingPerItem) ...[
+                  const SizedBox(height: 6),
+                  SizedBox(
+                    width: double.infinity,
+                    child: SegmentedButton<ConflictChoice>(
+                      segments: const [
+                        ButtonSegment(
+                          value: ConflictChoice.overwrite,
+                          label: Text('Overwrite'),
+                        ),
+                        ButtonSegment(
+                          value: ConflictChoice.keepBoth,
+                          label: Text('Keep both'),
+                        ),
+                        ButtonSegment(
+                          value: ConflictChoice.skip,
+                          label: Text('Skip'),
+                        ),
+                      ],
+                      selected: {_perItemChoices[conflict.item.id]!},
+                      showSelectedIcon: false,
+                      onSelectionChanged: (selection) => setState(() {
+                        _perItemChoices[conflict.item.id] = selection.first;
+                      }),
+                    ),
+                  ),
+                ],
+              ],
+            ),
+          ),
+        if (_decidingPerItem) ...[
+          const SizedBox(height: 8),
+          SizedBox(
+            width: double.infinity,
+            child: FilledButton(
+              onPressed: _confirmPerItem,
+              child: const Text('Confirm'),
+            ),
+          ),
+        ],
+      ],
+    );
+  }
+}

lib/widgets/share_sheet.dart

@@ -1,6 +1,9 @@
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
+import 'package:path/path.dart' as p;
+import 'package:path_provider/path_provider.dart';
 import 'package:provider/provider.dart';
+import 'package:share_plus/share_plus.dart';
 import '../models/nextcloud_item.dart';
 import '../models/nextcloud_share.dart';
 import '../models/nextcloud_sharee.dart';
@@ -67,6 +70,8 @@ class _ShareSheetState extends State<ShareSheet> {
   List<NextcloudShare> _inherited = [];
   List<NextcloudSharee> _searchResults = [];
   bool _isSearching = false;
+  bool _isAddingEmail = false;
+  bool _isSharingFile = false;
   final _searchController = TextEditingController();
   final _emailController = TextEditingController();
 
@@ -141,6 +146,7 @@ class _ShareSheetState extends State<ShareSheet> {
   Future<void> _addEmailShare() async {
     final email = _emailController.text.trim();
     if (email.isEmpty) return;
+    setState(() => _isAddingEmail = true);
     final provider = context.read<ServerProvider>();
     final messenger = ScaffoldMessenger.of(context);
     final share = await provider.createShare(
@@ -150,6 +156,7 @@ class _ShareSheetState extends State<ShareSheet> {
     );
     if (!mounted) return;
     if (share == null) {
+      setState(() => _isAddingEmail = false);
       messenger.showSnackBar(
         const SnackBar(
           content: Text('Could not create email share'),
@@ -161,6 +168,7 @@ class _ShareSheetState extends State<ShareSheet> {
     setState(() {
       _shares = [..._shares, share];
       _emailController.clear();
+      _isAddingEmail = false;
     });
     messenger.showSnackBar(
       SnackBar(
@@ -217,6 +225,41 @@ class _ShareSheetState extends State<ShareSheet> {
     );
   }
 
+  /// Downloads the item to a scratch file and hands it to Android's native
+  /// "Share to..." sheet (`share_plus`) - a completely different action
+  /// from the rest of this sheet (which shares *within* Nextcloud, via
+  /// users/links) and the only one here that reads the file's actual
+  /// bytes.
+  Future<void> _shareFileDirectly() async {
+    final provider = context.read<ServerProvider>();
+    if (provider.service == null) return;
+    setState(() => _isSharingFile = true);
+    final messenger = ScaffoldMessenger.of(context);
+    try {
+      final tempDir = await getTemporaryDirectory();
+      final tempPath = p.join(tempDir.path, widget.item.name);
+      await provider.service!.downloadToFile(widget.item.path, tempPath);
+      if (!mounted) return;
+      await SharePlus.instance.share(
+        ShareParams(
+          files: [XFile(tempPath)],
+          fileNameOverrides: [widget.item.name],
+        ),
+      );
+    } catch (_) {
+      if (mounted) {
+        messenger.showSnackBar(
+          const SnackBar(
+            content: Text('Could not share the file'),
+            behavior: SnackBarBehavior.floating,
+          ),
+        );
+      }
+    } finally {
+      if (mounted) setState(() => _isSharingFile = false);
+    }
+  }
+
   Widget _sectionHeader(String label) {
     final theme = Theme.of(context);
     final colorScheme = theme.colorScheme;
@@ -314,17 +357,43 @@ class _ShareSheetState extends State<ShareSheet> {
           item: widget.item,
           padding: const EdgeInsets.only(top: 12, bottom: 8),
         ),
-        const SizedBox(height: 8),
+        if (!widget.item.isFolder) ...[
+          const SizedBox(height: 4),
+          ListTile(
+            contentPadding: EdgeInsets.zero,
+            leading: _isSharingFile
+                ? const Padding(
+                    padding: EdgeInsets.all(12),
+                    child: SizedBox(
+                      width: 20,
+                      height: 20,
+                      child: CircularProgressIndicator(strokeWidth: 2),
+                    ),
+                  )
+                : const Icon(Icons.ios_share_rounded),
+            title: const Text('Share file directly'),
+            subtitle: const Text('Send the file itself via another app'),
+            onTap: _isSharingFile ? null : _shareFileDirectly,
+          ),
+          const SizedBox(height: 12),
+          const Divider(),
+        ],
+        const SizedBox(height: 12),
         _sectionHeader('Internal shares'),
         const SizedBox(height: 8),
         TextField(
           controller: _searchController,
           decoration: InputDecoration(
+            isDense: true,
+            contentPadding: const EdgeInsets.symmetric(
+              horizontal: 16,
+              vertical: 12,
+            ),
             hintText: 'Type names or teams',
             prefixIcon: const Icon(Icons.search_rounded),
             suffixIcon: _isSearching
                 ? const Padding(
-                    padding: EdgeInsets.all(14),
+                    padding: EdgeInsets.all(12),
                     child: SizedBox(
                       width: 16,
                       height: 16,
@@ -381,9 +450,25 @@ class _ShareSheetState extends State<ShareSheet> {
         TextField(
           controller: _emailController,
           keyboardType: TextInputType.emailAddress,
+          enabled: !_isAddingEmail,
           decoration: InputDecoration(
+            isDense: true,
+            contentPadding: const EdgeInsets.symmetric(
+              horizontal: 16,
+              vertical: 12,
+            ),
             hintText: 'Type an email',
             prefixIcon: const Icon(Icons.email_rounded),
+            suffixIcon: _isAddingEmail
+                ? const Padding(
+                    padding: EdgeInsets.all(12),
+                    child: SizedBox(
+                      width: 16,
+                      height: 16,
+                      child: CircularProgressIndicator(strokeWidth: 2),
+                    ),
+                  )
+                : null,
             border: OutlineInputBorder(borderRadius: BorderRadius.circular(16)),
             filled: true,
             fillColor: colorScheme.surfaceContainerLow,