feat(usage): split throttle thresholds per bucket, add draggable gauge markers

src/ClaudeDo.Ui/Views/WindowDialogService.cs

@@ -62,7 +62,9 @@ public sealed class WindowDialogService : IDialogService
     {
         var dlg = new UsageMonitorModalView { DataContext = vm };
         vm.CloseAction = () => dlg.Close();
-        await dlg.ShowDialog(_owner);
+        // The pill sits in both the footer and the Mission Control header, so own the dialog to
+        // whichever window is active — otherwise it opens behind Mission Control.
+        await dlg.ShowDialog(ActiveOwner());
     }
 
     public async Task ShowSettingsAsync(SettingsModalViewModel vm)