design: the code-set state colours now agree with the standard

Last inconsistency from the sweep: several VM-side state colours are still literals, and after
the palette moved they disagreed with everything around them — the top bar's LIVE state would
have painted the retired pink-red while the tile beside it used the standard red.

Values aligned (tokenisation of these sites is its own unit — they are strings bound to
Background/Foreground, so the fix is a VM->Brush refactor, not a find/replace):
- live / on-air / recorder dot: #e94560 -> #ff5451 (the standard red)
- error banner: #8f1f1f -> #93000a (error-container)
- audio meter bands follow the doc's stated thresholds: nominal cyan #38bdf8, caution amber
  #ffb95f, peak #ff5451 — they were green/yellow/red, which contradicted DESIGN.md's own table

GameMeterHonestyTests pinned the old band colours; its intent (the meter scales by volume) is
unchanged, so the two colour expectations now name the new bands.

ViewModels/MainViewModel.Audio.cs

@@ -68,9 +68,9 @@ public partial class MainViewModel
 
     public string MeterBrush => MeterLevel switch
     {
-        < 0.6 => "#22c55e",
-        < 0.8 => "#eab308",
-        _ => "#ef4444",
+        < 0.6 => "#38bdf8",
+        < 0.8 => "#ffb95f",
+        _ => "#ff5451",
     };
 
     /// <summary>Previewes the volume position while the slider is dragged; the
@@ -283,9 +283,9 @@ public partial class MainViewModel
 
     public string GameMeterBrush => GameMeterLevel switch
     {
-        < 0.6 => "#22c55e",
-        < 0.8 => "#eab308",
-        _ => "#ef4444",
+        < 0.6 => "#38bdf8",
+        < 0.8 => "#ffb95f",
+        _ => "#ff5451",
     };
 
     public void SetGameVolumeAdjusting(bool adjusting)

ViewModels/MainViewModel.Streaming.Operations.cs

@@ -316,7 +316,7 @@ public partial class MainViewModel : ViewModelBase
             return;
         }
 
-        HealthIssueBackground = report.IsError ? "#8f1f1f" : "#b8860b";
+        HealthIssueBackground = report.IsError ? "#93000a" : "#b8860b";
         HealthIssueBanner = report.Text;
     }
 
@@ -486,8 +486,8 @@ public partial class MainViewModel : ViewModelBase
         var live = IsLive;
         // A live TEST broadcast wears gold, not the live red — the TEST badge +
         // gold are the "this is a rehearsal" cue (TASK 41).
-        TopBarBackground = live ? IsTestStream ? "#9c6f1c" : "#e94560" : "#16213e";
-        PreviewGlowBrush = live ? IsTestStream ? "#9c6f1c" : "#e94560" : "Transparent";
+        TopBarBackground = live ? IsTestStream ? "#9c6f1c" : "#ff5451" : "#16213e";
+        PreviewGlowBrush = live ? IsTestStream ? "#9c6f1c" : "#ff5451" : "Transparent";
         PreviewGlowThickness = live ? new Thickness(3) : new Thickness(0);
 
         if (!live) _healthPollTimer.Stop();

ViewModels/MainViewModel.Streaming.cs

@@ -87,10 +87,10 @@ public partial class MainViewModel : ViewModelBase
     public bool IsOffline => StreamStatus == StreamStatus.Offline;
     public bool IsLive => StreamStatus == StreamStatus.Streaming;
     public bool IsLivePrivate => IsLive && string.Equals(StreamVisibility, "Private", StringComparison.OrdinalIgnoreCase);
-    public string RecDotBrush => !IsRecording ? "#555555" : "#e94560";
+    public string RecDotBrush => !IsRecording ? "#555555" : "#ff5451";
     public string RecTextBrush => (IsLive || IsRecording) ? "#ffffff" : "#888888";
     public double RecDotOpacity => IsRecording ? _recDotPulse : 0.55;
-    public string OnAirBrush => !IsLive ? "#555555" : IsLivePrivate ? "#22c55e" : "#e94560";
+    public string OnAirBrush => !IsLive ? "#555555" : IsLivePrivate ? "#22c55e" : "#ff5451";
 
     // ─── REC / ON-AIR pills (TASK 18) ───
     public bool RecordPillOn
@@ -222,7 +222,7 @@ public partial class MainViewModel : ViewModelBase
     /// <summary>Reality dot color, one meaning per mode: gold = test, red = live,
     /// green = recording. The pre-spec pulsing lamp never shipped; the word + bar
     /// color carry the state and the dot just pins it.</summary>
-    public string RunningDotBrush => IsTestStream ? "#9c6f1c" : IsLive ? "#e94560" : "#22c55e";
+    public string RunningDotBrush => IsTestStream ? "#9c6f1c" : IsLive ? "#ff5451" : "#22c55e";
 
     /// <summary>Raises every flag the top bar renders, so any state change re-renders
     /// exactly the world that is now true.</summary>

ytLive.Tests/GameMeterHonestyTests.cs

@@ -48,14 +48,14 @@ public sealed class GameMeterHonestyTests
             vm.GameAudioVolume = 1.0;
             vm.GameAudioLevel = 1.0;
             Assert.True(vm.GameMeterFillWidth > 230, "unity volume must keep the meter hot");
-            Assert.Equal("#ef4444", vm.GameMeterBrush);
+            Assert.Equal("#ff5451", vm.GameMeterBrush);   // DESIGN.md: peak band
 
             // Drop the knob to 20% — the captured level does NOT change (the OS
             // tap is pre-endpoint-volume); the meter must scale it anyway.
             vm.GameAudioVolume = 0.2;
             vm.GameAudioLevel = 1.0;
             Assert.InRange(vm.GameMeterFillWidth, 40, 80);
-            Assert.Equal("#22c55e", vm.GameMeterBrush);
+            Assert.Equal("#38bdf8", vm.GameMeterBrush);   // DESIGN.md: nominal band
 
             // And the push really reached the (faked) endpoint — one knob, honest.
             Assert.Contains(0.2, pushed);