fix: isolate Windows sample playback for NAudio 3

MeetingAssistant/Program.cs

@@ -132,7 +132,11 @@ builder.Services.AddSingleton<IMeetingSummaryRetryRunner, MeetingSummaryRetryRun
 builder.Services.AddSingleton<IMeetingWorkflowRulesProvider, FileMeetingWorkflowRulesProvider>();
 builder.Services.AddSingleton<IMeetingWorkflowEngine, MeetingWorkflowEngine>();
 builder.Services.AddSingleton<IWorkflowRulesEditorInstructionBuilder, WorkflowRulesEditorInstructionBuilder>();
+#if WINDOWS
 builder.Services.AddSingleton<IWorkflowRulesEditorSamplePlaybackQueue, WorkflowRulesEditorSamplePlaybackQueue>();
+#else
+builder.Services.AddSingleton<IWorkflowRulesEditorSamplePlaybackQueue, UnavailableWorkflowRulesEditorSamplePlaybackQueue>();
+#endif
 builder.Services.AddSingleton<IWorkflowRulesEditorChatPipeline, WorkflowRulesEditorChatPipeline>();
 builder.Services.AddTransient<WorkflowRulesEditorChatViewModel>();
 #if WINDOWS

MeetingAssistant/Workflow/WorkflowRulesEditorSamplePlaybackQueue.cs

@@ -8,6 +8,7 @@ public interface IWorkflowRulesEditorSamplePlaybackQueue
     Task<string> QueueAsync(int sampleId, byte[] wavBytes, CancellationToken cancellationToken = default);
 }
 
+#if WINDOWS
 public sealed class WorkflowRulesEditorSamplePlaybackQueue : IWorkflowRulesEditorSamplePlaybackQueue, IDisposable
 {
     private readonly Channel<QueuedSample> channel = Channel.CreateUnbounded<QueuedSample>();
@@ -98,3 +99,13 @@ public sealed class WorkflowRulesEditorSamplePlaybackQueue : IWorkflowRulesEdito
 
     private sealed record QueuedSample(int SampleId, byte[] WavBytes);
 }
+#else
+public sealed class UnavailableWorkflowRulesEditorSamplePlaybackQueue : IWorkflowRulesEditorSamplePlaybackQueue
+{
+    public Task<string> QueueAsync(int sampleId, byte[] wavBytes, CancellationToken cancellationToken = default)
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        return Task.FromResult("Speaker sample playback requires the Windows build of Meeting Assistant.");
+    }
+}
+#endif