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

tests/ClaudeDo.Ui.Tests/ViewModels/SettingsModalViewModelTests.cs

@@ -43,6 +43,33 @@ public class SettingsModalViewModelTests
             SessionSkills: null, ModelPresets: null,
             UsageGateFiveHourPct: fiveHourPct, UsageGateSevenDayPct: sevenDayPct);
 
+    [Fact]
+    public async Task Save_carries_dragged_throttle_stages_through_untouched()
+    {
+        // The throttle stages are only editable by dragging the usage-monitor gauges. Saving the
+        // Settings modal rebuilds the whole DTO, so it must not reset them to the defaults.
+        var worker = new FakeWorker
+        {
+            AppToReturn = DtoWith(65, 95) with
+            {
+                UsageThrottleFiveHourSoftPct = 42,
+                UsageThrottleFiveHourHardPct = 58,
+                UsageThrottleSevenDaySoftPct = 71,
+                UsageThrottleSevenDayHardPct = 88,
+            },
+        };
+        var vm = MakeVm(worker);
+        await vm.LoadAsync();
+
+        await vm.SaveCommand.ExecuteAsync(null);
+
+        Assert.NotNull(worker.Saved);
+        Assert.Equal(42, worker.Saved!.UsageThrottleFiveHourSoftPct);
+        Assert.Equal(58, worker.Saved.UsageThrottleFiveHourHardPct);
+        Assert.Equal(71, worker.Saved.UsageThrottleSevenDaySoftPct);
+        Assert.Equal(88, worker.Saved.UsageThrottleSevenDayHardPct);
+    }
+
     private static SettingsModalViewModel MakeVm(FakeWorker worker) =>
         new(worker, new PrimeClaudeTabViewModel(new FakePrimeApi()), new OnlineLoginService(),
             MakeLocalizer(), new AppSettings());