Cookies: keep every site of an imported file (no site picker); only the cookies box takes drops on Settings

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

apps/desktop/lib/src/shell/app_shell.dart

@@ -501,7 +501,9 @@ class AppShellState extends State<AppShell> with SingleTickerProviderStateMixin
     _selectTab(ShellTab.library);
   }
 
+  // Off on Settings: its own drop targets (cookies) take the files there.
   Widget _dropTarget(Widget child) => DropTarget(
+        enable: _tab != ShellTab.settings,
         onDragEntered: (_) => setState(() => _dragging = _onTop),
         onDragExited: (_) => setState(() => _dragging = false),
         onDragDone: (d) {