[fix](trx-server): honor per-rig audio bind addresses

Use each rig's configured audio listener unless --listen explicitly overrides all bind addresses. Keep preflight socket validation consistent with runtime behavior.

Assisted-By: OpenAI Codex (GPT-5)
Signed-off-by: Stan Grams <sjg@haxx.space>

src/trx-server/src/main.rs

@@ -922,11 +922,10 @@ fn bound_sockets(cli: &Cli, cfg: &ServerConfig, rigs: &[RigInstanceConfig]) -> V
             "[listen]",
         ));
     }
-    let audio_ip = cli.listen.unwrap_or(cfg.audio.listen);
     for rig in rigs {
         if rig.audio.enabled {
             sockets.push(BoundSocket::new(
-                audio_ip,
+                cli.listen.unwrap_or(rig.audio.listen),
                 rig.audio.port,
                 format!("rig \"{}\" [audio]", rig.id),
             ));
@@ -1276,9 +1275,9 @@ async fn main() -> DynResult<()> {
             }
         }));
 
-        // Spawn audio stack.
-        // listen_override priority: --listen CLI flag > global [audio].listen > per-rig default.
-        let audio_listen_override = cli.listen.or(Some(cfg.audio.listen));
+        // Spawn audio stack. --listen overrides every configured bind address;
+        // otherwise each rig keeps its own [rigs.audio].listen value.
+        let audio_listen_override = cli.listen;
         #[cfg(feature = "soapysdr")]
         let audio_vchan_manager = sdr_vchan_manager.clone();
         #[cfg(not(feature = "soapysdr"))]
@@ -1417,6 +1416,40 @@ mod tests {
         assert!(parse_serial_addr("   ").is_err());
     }
 
+    #[test]
+    fn bound_sockets_preserves_per_rig_audio_addresses() {
+        let cli = Cli::parse_from(["trx-server"]);
+        let cfg = ServerConfig::default();
+        let mut local = RigInstanceConfig::default();
+        local.id = "local".into();
+        local.audio.listen = "127.0.0.1".parse().unwrap();
+        local.audio.port = 4531;
+        let mut remote = RigInstanceConfig::default();
+        remote.id = "remote".into();
+        remote.audio.listen = "0.0.0.0".parse().unwrap();
+        remote.audio.port = 4532;
+
+        let sockets = bound_sockets(&cli, &cfg, &[local, remote]);
+        let local = sockets.iter().find(|s| s.port == 4531).unwrap();
+        let remote = sockets.iter().find(|s| s.port == 4532).unwrap();
+        assert_eq!(local.addr, "127.0.0.1".parse::<IpAddr>().unwrap());
+        assert_eq!(remote.addr, "0.0.0.0".parse::<IpAddr>().unwrap());
+    }
+
+    #[test]
+    fn bound_sockets_applies_cli_listen_to_every_audio_listener() {
+        let cli = Cli::parse_from(["trx-server", "--listen", "192.0.2.10"]);
+        let cfg = ServerConfig::default();
+        let mut rig = RigInstanceConfig::default();
+        rig.id = "remote".into();
+        rig.audio.listen = "127.0.0.1".parse().unwrap();
+        rig.audio.port = 4532;
+
+        let sockets = bound_sockets(&cli, &cfg, &[rig]);
+        let audio = sockets.iter().find(|s| s.port == 4532).unwrap();
+        assert_eq!(audio.addr, "192.0.2.10".parse::<IpAddr>().unwrap());
+    }
+
     #[test]
     fn default_audio_bandwidth_for_mode_table() {
         assert_eq!(default_audio_bandwidth_for_mode(&RigMode::USB), 3_000);