Add Trash/Shares/Recent tabs, file sharing, Details sheet, and rebrand to Noo

Major additions since the initial rebuild:
- New tabs: Trash, Shares, Recent, configurable tab visibility/order/default
- Nextcloud sharing: search users/teams, internal link, email shares,
  public links, "others with access" - in its own Share bottom sheet
- Details bottom sheet (Info/Versions/Activity) with a persistent peek
  panel in the media viewer, reachable from selection, swipe, and the
  media viewer
- Files/Photos: tap-and-hold multi-select with a sticky selection toolbar,
  swipe actions (favorite/delete/share), sticky sort/filter controls,
  list/grid views, breadcrumb chips, whole-account Photos view
- Media viewer: pinch/double-tap zoom on images, predictive-back support,
  fixed PDF zoom-out floor
- Settings: Material You theming incl. AMOLED black, configurable bottom
  bar tabs, swipe actions, media seek bar style, and folder-listing cache
  policy (never/periodic/manual) to cut down on refetching
- Login flow moved to an in-app Chrome Custom Tab with retry-tolerant
  polling
- Replaced ad hoc widgets with native Material 3 equivalents (toggle
  IconButtons, SliverAppBar selection toolbar, SearchBar, drag handles)
- Rebrand: app renamed to Noo throughout, package id -> dev.ayushya.noo,
  new adaptive launcher icon

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

lib/models/nextcloud_share.dart

@@ -0,0 +1,42 @@
+import 'nextcloud_item.dart';
+
+enum ShareType { user, group, publicLink, email, federated, other }
+
+/// A Nextcloud OCS share — either something the current user has shared
+/// with someone else, or something someone else has shared with them
+/// (distinguished by [sharedWithMe]).
+class NextcloudShare {
+  final String id;
+  final String path;
+  final String name;
+  final NextcloudItemType itemType;
+  final ShareType shareType;
+  final String ownerDisplayName;
+  final String? sharedWithDisplayName;
+  final DateTime sharedAt;
+  final bool sharedWithMe;
+
+  /// Only set for public-link shares.
+  final String? url;
+  final int permissions;
+  final String? token;
+  final DateTime? expireDate;
+
+  const NextcloudShare({
+    required this.id,
+    required this.path,
+    required this.name,
+    required this.itemType,
+    required this.shareType,
+    required this.ownerDisplayName,
+    this.sharedWithDisplayName,
+    required this.sharedAt,
+    required this.sharedWithMe,
+    this.url,
+    this.permissions = 1,
+    this.token,
+    this.expireDate,
+  });
+
+  bool get isFolder => itemType == NextcloudItemType.folder;
+}