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

src/ClaudeDo.Worker/Usage/UsageSnapshotBuilder.cs

@@ -49,13 +49,18 @@ public sealed class UsageSnapshotBuilder
             .Select(l => new UsageLimitDto(l.Kind, l.Group, l.Percent, l.Severity, l.ResetsAt, l.ScopeModelDisplayName, l.IsActive))
             .ToList();
 
+        var fiveHourThresholds = new UsageThresholds(
+            settings.UsageThrottleFiveHourSoftPct, settings.UsageThrottleFiveHourHardPct, settings.UsageGateFiveHourPct);
+        var sevenDayThresholds = new UsageThresholds(
+            settings.UsageThrottleSevenDaySoftPct, settings.UsageThrottleSevenDayHardPct, settings.UsageGateSevenDayPct);
+
         var configuredSlots = Math.Max(1, settings.MaxParallelExecutions);
         var effectiveSlots = snapshot is null || lastError is not null
             ? configuredSlots
             : UsageThrottle.EffectiveSlots(
-                configuredSlots, snapshot.FiveHour?.Utilization, snapshot.SevenDay?.Utilization,
-                settings.UsageThrottleSoftPct, settings.UsageThrottleHardPct,
-                settings.UsageGateFiveHourPct, settings.UsageGateSevenDayPct);
+                configuredSlots,
+                snapshot.FiveHour?.Utilization, fiveHourThresholds,
+                snapshot.SevenDay?.Utilization, sevenDayThresholds);
         var throttleBucket = effectiveSlots < configuredSlots
             ? DecisiveBucket(snapshot?.FiveHour?.Utilization, snapshot?.SevenDay?.Utilization)
             : null;
@@ -75,7 +80,11 @@ public sealed class UsageSnapshotBuilder
             lastError,
             configuredSlots,
             effectiveSlots,
-            throttleBucket);
+            throttleBucket,
+            fiveHourThresholds.SoftPct,
+            fiveHourThresholds.HardPct,
+            sevenDayThresholds.SoftPct,
+            sevenDayThresholds.HardPct);
     }
 
     private static string? DecisiveBucket(double? fiveHourPct, double? sevenDayPct)