[feat](trx-server): add audio capture and TCP streaming

Add AudioConfig to server configuration with support for RX capture
and TX playback via cpal and Opus encoding. Run a dedicated TCP
listener (default port 4533) that sends StreamInfo on connect, streams
RX Opus frames to clients, and receives TX frames back.

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

src/trx-server/Cargo.toml

@@ -18,5 +18,8 @@ tracing-subscriber = { workspace = true }
 clap = { workspace = true, features = ["derive"] }
 dirs = "6"
 libloading = "0.8"
+bytes = "1"
+cpal = "0.15"
+opus = "0.3"
 trx-backend = { path = "trx-backend" }
 trx-core = { path = "../trx-core" }