[feat](trx-rs): show audio bitrate and active stream count on About page

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Signed-off-by: Stan Grams <sjg@haxx.space>

src/trx-server/src/main.rs

@@ -484,6 +484,7 @@ fn spawn_rig_audio_stack(
         sample_rate: rig_cfg.audio.sample_rate,
         channels: rig_cfg.audio.channels,
         frame_duration_ms: rig_cfg.audio.frame_duration_ms,
+        bitrate_bps: rig_cfg.audio.bitrate_bps,
     };
 
     let (rx_audio_tx, _) = broadcast::channel::<Bytes>(256);