Beep cleanup: start before Task.Run + Wait timeout to avoid orphaned task

tests/02-wakeword-cs/Program.cs

@@ -165,7 +165,6 @@ static void FireAndForgetBeep(int device, short[] beepBuffer)
     {
         int remaining = beepBuffer.Length - offset;
         int take = (int)Math.Min(frameCount, (uint)remaining);
-        int silence = (int)frameCount - take;
         unsafe
         {
             short* dst = (short*)output.ToPointer();
@@ -187,15 +186,27 @@ static void FireAndForgetBeep(int device, short[] beepBuffer)
 
     var stream = new Stream(
         null, outParams, WakewordModel.SampleRate, 1024, StreamFlags.NoFlag, playCb, IntPtr.Zero);
+    try
+    {
+        stream.Start();
+    }
+    catch
+    {
+        stream.Dispose();
+        done.Dispose();
+        throw;
+    }
     Task.Run(() =>
     {
-        done.Wait();
+        // 2 s timeout so a failed callback (which PortAudio silently swallows
+        // and would leave 'done' unset) eventually releases the stream + handle
+        // instead of leaking them for the process lifetime.
+        done.Wait(TimeSpan.FromSeconds(2));
         Thread.Sleep(200);
         stream.Stop();
         stream.Dispose();
         done.Dispose();
     });
-    stream.Start();
 }
 
 static class Libc