Polish floating bottom bar: elevation, height, overlap, and FAB shape

- Give the floating bar and search satellite the app's one shadow
  (nooDialogShadow) plus a smaller, tighter height on both platforms.
- Let every tab's scrollable list compute its own bottom clearance
  (bottomBarClearance) instead of a flat 100px, so the floating bar no
  longer overlaps the last row/card.
- Square the Android upload FAB off to a rounded-square radius when the
  bottom bar is attached, keeping it fully round only when floating.
- Let a swipe on a file row trigger its action directly once dragged
  past 1.8x the reveal width, instead of requiring a second tap.

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

lib/views/favorites_view.dart

@@ -29,6 +29,7 @@ import '../widgets/noo/overlays/noo_sheet.dart';
 import '../widgets/noo/core/noo_button.dart';
 import '../widgets/share_sheet.dart';
 import '../widgets/sticky_header_delegate.dart';
+import '../widgets/tabs/tab_state_slivers.dart';
 import '../widgets/synced_header_scaffold.dart' show formatBytes;
 import 'file_viewer_screen.dart';
 import 'move_copy_destination_picker.dart';
@@ -638,7 +639,7 @@ class _FavoritesViewState extends State<FavoritesView> {
             }, childCount: favorites.length),
           ),
         ),
-      const SliverToBoxAdapter(child: SizedBox(height: 100)),
+      SliverToBoxAdapter(child: SizedBox(height: bottomBarClearance(context))),
     ];
 
     return PopScope(