v3.9.1: plain/WASAPI streams now play on an ASIO-mode receiver (silent-mic fix)

Receiver: a Mixed (plain) session is rendered on an active lane in BothIndependent mode instead of being skipped, so a WASAPI-only sender is no longer silent to a receiver that has an ASIO driver selected. Also port the per-session buffer depth-drain (stops the receive jitter buffer bloating).

Sender: add sndAudFr meter (audio frames actually sent) to localise capture vs send.

App: startup sound cue (machine-wide, Preferences); stop sending audio when no peer is reachable (issue #8). Version 3.9.1.

Server (relay): fix updater version-compare for multi-dot tags, guard the main loop against crashes, reject spoofed BYE from a mismatched endpoint.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/RemSound.Sender/AudioSender.cs

@@ -188,6 +188,15 @@ public sealed class AudioSender : IDisposable
         return a > b ? a : b;
     }
 
+    /// <summary>Total audio frames both lanes actually handed to the wire since the last call
+    /// (resets on read). Pairs with <see cref="TakeMaxSenderPreEncodePeak"/> on the diag line:
+    /// capPeak proves real signal reached the encoder; this proves frames left the socket. A
+    /// high capPeak with zero frames sent localises a silence to the encode/encrypt stage — the
+    /// missing measurement behind the "mic only works in ASIO" report. In WasapiOnly mode only
+    /// defaultLane fires, so this number IS the WASAPI mic lane's output.</summary>
+    public long TakeSenderAudioFramesSent() =>
+        defaultLane.TakeAudioFramesSent() + asioLane.TakeAudioFramesSent();
+
     // Cross-buffer (boundary) and within-buffer (content) split — see AudioStepProbe for the
     // diagnostic distinction. Used by the per-second diag logger to emit two extra columns so
     // an offline log inspection can tell a real audio transient apart from a buffer-boundary

src/RemSound.Sender/SenderLane.cs

@@ -83,6 +83,17 @@ internal sealed class SenderLane
     private float preEncodePeak;
     public float TakeMaxPreEncodePeak() { var p = preEncodePeak; preEncodePeak = 0f; return p; }
 
+    // Count of audio frames this lane actually handed to the wire (encode AND encrypt both
+    // succeeded → SendAudio / SendPcmPart called) since the last drain. Pairs with preEncodePeak:
+    // capPeak proves real signal reached the encoder INPUT, but every post-encode early-return —
+    // the Opus encoder returning len<=0, no password so cryptoGcm is null, or the accumulator
+    // never completing a frame — is INVISIBLE to it. This counts what actually left the machine,
+    // so a log can finally tell "mic captured but nothing sent" (a drop at encode/encrypt) from
+    // "mic captured and sent" (the silence is downstream). Added 2026-06-12 for Andre's
+    // WASAPI-mic-only-works-in-ASIO investigation. Reset on read, like the peak.
+    private long audioFramesSent;
+    public long TakeAudioFramesSent() => Interlocked.Exchange(ref audioFramesSent, 0);
+
     // Which render route this lane announces in its format packets. The receiver reads the
     // Lane byte on the wire and tags the matching SessionPlayout, which makes PlayoutEngine
     // route the lane's audio to the corresponding per-route IWaveProvider surface (lane
@@ -297,6 +308,7 @@ internal sealed class SenderLane
         var maxPart = RemPacket.MaxAudioPayloadBytes;
         var totalParts = (byte)((ctLen + maxPart - 1) / maxPart);
         pcmFrameId++;
+        Interlocked.Increment(ref audioFramesSent);
         for (byte part = 0; part < totalParts; part++)
         {
             var offset = part * maxPart;
@@ -324,6 +336,7 @@ internal sealed class SenderLane
         EnsureCrypto();
         if (cryptoGcm is null) return; // no password yet → never send audio in the clear
         var ctLen = RemSoundCrypto.EncryptInto(cryptoGcm, opusBytes, cipherScratch);
+        Interlocked.Increment(ref audioFramesSent);
         SendAudio(cipherScratch.AsSpan(0, ctLen));
     }