Add adaptive packet loss handling

proto/voicecat.proto

@@ -47,6 +47,7 @@ message Envelope {
     SubscribeVoiceRequest   subscribe_voice     = 45;
     UnsubscribeVoiceRequest unsubscribe_voice   = 46;
     VoiceSubscriptionResult voice_subscription_result = 47;
+    PacketLossUpdate    packet_loss_update       = 48;
 
     // Text (50-59)
     TextMessage          text_message           = 50;
@@ -77,6 +78,12 @@ enum ChannelMode  { MODE_MONO = 0; MODE_STEREO = 1; }
 enum StreamKind   { STREAM_MIC = 0; STREAM_SCREEN_AUDIO = 1; STREAM_AUX_DEVICE = 2; }
 enum TextScope    { TEXT_CHANNEL = 0; TEXT_PRIVATE = 1; TEXT_SERVER = 2; }
 enum OpusApplication { OPUS_VOIP = 0; OPUS_AUDIO = 1; OPUS_LOWDELAY = 2; }
+enum PacketLossMode {
+  PACKET_LOSS_MANUAL = 0;
+  PACKET_LOSS_AUTO_FAST = 1;
+  PACKET_LOSS_AUTO_BALANCED = 2;
+  PACKET_LOSS_AUTO_STABLE = 3;
+}
 
 // Common types
 message AudioConfig {
@@ -91,6 +98,7 @@ message AudioConfig {
   bool   dtx = 9;
   uint32 complexity = 10;           // 0..10
   bool   dred = 11;                 // Deep REDundancy (Opus 1.6)
+  PacketLossMode packet_loss_mode = 12;
 }
 
 message StreamInfo {
@@ -223,6 +231,11 @@ message UdpBinding          { bytes udp_token = 1; bool ack = 2; }
 message SubscribeVoiceRequest   {}
 message UnsubscribeVoiceRequest {}
 message VoiceSubscriptionResult { bool ok = 1; string error = 2; bool subscribed = 3; }
+message PacketLossUpdate {
+  uint32 channel_id = 1;
+  uint32 measured_percent = 2;
+  uint32 applied_percent = 3;
+}
 
 //  Text
 message TextMessage {