[refactor](decoders): extract CW decoder into trx-cw crate

Move the Goertzel-based CW decoder out of trx-server::decode::cw into
a dedicated src/decoders/trx-cw crate, matching the layout of trx-aprs,
trx-ft8, and trx-wspr. The decode module is now empty and removed.

- src/decoders/trx-cw/ (new — Goertzel + Morse decoder)
- trx-server: drop decode module entirely, use trx_cw::CwDecoder
- CwEvent stays in trx-core (mirrors AprsPacket / Ft8Message / WsprMessage)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/decoders/trx-cw/Cargo.toml

@@ -0,0 +1,11 @@
+# SPDX-FileCopyrightText: 2026 Stanislaw Grams <stanislawgrams@gmail.com>
+#
+# SPDX-License-Identifier: BSD-2-Clause
+
+[package]
+name = "trx-cw"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+trx-core = { path = "../../trx-core" }

src/trx-server/Cargo.toml

@@ -25,6 +25,7 @@ trx-app = { path = "../trx-app" }
 trx-backend = { path = "trx-backend" }
 trx-core = { path = "../trx-core" }
 trx-aprs = { path = "../decoders/trx-aprs" }
+trx-cw = { path = "../decoders/trx-cw" }
 trx-ft8 = { path = "../decoders/trx-ft8" }
 trx-wspr = { path = "../decoders/trx-wspr" }
 trx-protocol = { path = "../trx-protocol" }

src/trx-server/src/audio.rs

@@ -23,11 +23,11 @@ use trx_core::audio::{
 use trx_core::decode::{AprsPacket, DecodedMessage, Ft8Message, WsprMessage};
 use trx_core::rig::state::{RigMode, RigState};
 use trx_aprs::AprsDecoder;
+use trx_cw::CwDecoder;
 use trx_ft8::Ft8Decoder;
 use trx_wspr::WsprDecoder;
 
 use crate::config::AudioConfig;
-use crate::decode;
 use crate::decode_logs::DecoderLoggers;
 
 const APRS_HISTORY_RETENTION: Duration = Duration::from_secs(24 * 60 * 60);
@@ -765,7 +765,7 @@ pub async fn run_cw_decoder(
     decode_logs: Option<Arc<DecoderLoggers>>,
 ) {
     info!("CW decoder started ({}Hz, {} ch)", sample_rate, channels);
-    let mut decoder = decode::cw::CwDecoder::new(sample_rate);
+    let mut decoder = CwDecoder::new(sample_rate);
     let mut was_active = false;
     let mut last_reset_seq: u64 = 0;
     let mut active = matches!(state_rx.borrow().status.mode, RigMode::CW | RigMode::CWR);

src/trx-server/src/decode/mod.rs

@@ -1,5 +0,0 @@
-// SPDX-FileCopyrightText: 2025 Stanislaw Grams <stanislawgrams@gmail.com>
-//
-// SPDX-License-Identifier: BSD-2-Clause
-
-pub mod cw;

src/trx-server/src/main.rs

@@ -5,7 +5,6 @@
 mod aprsfi;
 mod audio;
 mod config;
-mod decode;
 mod decode_logs;
 mod error;
 mod listener;