fix(visualizer): ease playhead re-anchor to kill startup jitter; gate diagnostics off (P10 W1)

DeepDrftPublic.Client/Controls/MixWaveformVisualizer.razor.cs

@@ -58,7 +58,7 @@ public partial class MixWaveformVisualizer : ComponentBase, IAsyncDisposable
     // datum-fetch / subscription / playback-coupling seams log to the browser console (prefixed
     // `[MixVisualizer]`, same as the JS logs so the two interleave into one timeline). These pinpoint
     // which upstream link is broken when the ribbon stays blank — set false once confirmed healthy.
-    private const bool Debug = true;
+    private const bool Debug = false;
     private const string Tag = "[MixVisualizer]";
 
     private static void DebugLog(string message)