[feat](trx-client): relay server-side decoded messages to frontends

Handle APRS/CW decode message types (0x03/0x04) in audio_client,
deserialize and forward via broadcast channel.  Create decode channel
and pass to audio client and HTTP frontend.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Signed-off-by: Stanislaw Grams <stanislawgrams@gmail.com>

src/trx-client/src/audio_client.rs

@@ -15,9 +15,10 @@ use tokio::time;
 use tracing::{info, warn};
 
 use trx_core::audio::{
-    read_audio_msg, write_audio_msg, AudioStreamInfo, AUDIO_MSG_RX_FRAME, AUDIO_MSG_STREAM_INFO,
-    AUDIO_MSG_TX_FRAME,
+    read_audio_msg, write_audio_msg, AudioStreamInfo, AUDIO_MSG_APRS_DECODE,
+    AUDIO_MSG_CW_DECODE, AUDIO_MSG_RX_FRAME, AUDIO_MSG_STREAM_INFO, AUDIO_MSG_TX_FRAME,
 };
+use trx_core::decode::DecodedMessage;
 
 /// Run the audio client with auto-reconnect.
 pub async fn run_audio_client(
@@ -25,6 +26,7 @@ pub async fn run_audio_client(
     rx_tx: broadcast::Sender<Bytes>,
     mut tx_rx: mpsc::Receiver<Bytes>,
     stream_info_tx: watch::Sender<Option<AudioStreamInfo>>,
+    decode_tx: broadcast::Sender<DecodedMessage>,
 ) {
     let mut reconnect_delay = Duration::from_secs(1);
 
@@ -34,7 +36,7 @@ pub async fn run_audio_client(
             Ok(stream) => {
                 reconnect_delay = Duration::from_secs(1);
                 if let Err(e) =
-                    handle_audio_connection(stream, &rx_tx, &mut tx_rx, &stream_info_tx).await
+                    handle_audio_connection(stream, &rx_tx, &mut tx_rx, &stream_info_tx, &decode_tx).await
                 {
                     warn!("Audio connection dropped: {}", e);
                 }
@@ -55,6 +57,7 @@ async fn handle_audio_connection(
     rx_tx: &broadcast::Sender<Bytes>,
     tx_rx: &mut mpsc::Receiver<Bytes>,
     stream_info_tx: &watch::Sender<Option<AudioStreamInfo>>,
+    decode_tx: &broadcast::Sender<DecodedMessage>,
 ) -> std::io::Result<()> {
     let (reader, writer) = stream.into_split();
     let mut reader = BufReader::new(reader);
@@ -78,12 +81,18 @@ async fn handle_audio_connection(
 
     // Spawn RX read task
     let rx_tx = rx_tx.clone();
+    let decode_tx = decode_tx.clone();
     let mut rx_handle = tokio::spawn(async move {
         loop {
             match read_audio_msg(&mut reader).await {
                 Ok((AUDIO_MSG_RX_FRAME, payload)) => {
                     let _ = rx_tx.send(Bytes::from(payload));
                 }
+                Ok((AUDIO_MSG_APRS_DECODE | AUDIO_MSG_CW_DECODE, payload)) => {
+                    if let Ok(msg) = serde_json::from_slice::<DecodedMessage>(&payload) {
+                        let _ = decode_tx.send(msg);
+                    }
+                }
                 Ok((msg_type, _)) => {
                     warn!("Audio client: unexpected message type {}", msg_type);
                 }