[feat](trx-client): add local cpal audio bridge for WSJT-X

Add configurable bidirectional local audio bridge (RX playback + TX capture) using cpal/opus for virtual-device routing on Linux/macOS, and document bridge settings.

Also expand rigctl frontend command compatibility aliases for hamlib/WSJT-X clients.

Co-authored-by: Codex <codex@openai.com>
Signed-off-by: Stanislaw Grams <stanislawgrams@gmail.com>

Cargo.lock

@@ -2222,7 +2222,9 @@ version = "0.1.0"
 dependencies = [
  "bytes",
  "clap",
+ "cpal",
  "dirs",
+ "opus",
  "serde",
  "serde_json",
  "tokio",