[feat](trx-configurator): add interactive configuration generator

New binary crate that generates trx-server.toml, trx-client.toml, or
trx-rs.toml via interactive prompts or --defaults mode. Produces
commented TOML using toml_edit with per-field descriptions.

Supports server config (general, rig, listen, audio, behavior) and
client config (general, remote, frontends). Hardware detection is
stubbed for future iteration.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Signed-off-by: Stan Grams <sjg@haxx.space>

Cargo.toml

@@ -26,6 +26,7 @@ members = [
     "src/trx-client/trx-frontend/trx-frontend-http",
     "src/trx-client/trx-frontend/trx-frontend-http-json",
     "src/trx-client/trx-frontend/trx-frontend-rigctl",
+    "src/trx-configurator",
 ]
 resolver = "2"