[feat](trx-rs): expose WFM stereo denoise toggle in UI

Wire the StereoDenoise processor through the full stack:
- Add SetWfmDenoise command variant and RigCat trait method (trx-core)
- Add wfm_denoise field to RigFilterState with default true
- Add protocol command and bidirectional mapping (trx-protocol)
- Add rig_task command handler (trx-server)
- Implement set_wfm_denoise in SoapySdrRig backend
- Add /set_wfm_denoise API endpoint (trx-frontend-http)
- Add denoise checkbox in WFM controls with SSE sync and
  localStorage persistence

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

src/trx-client/trx-frontend/trx-frontend-http/assets/web/app.js

@@ -1373,6 +1373,12 @@ function render(update) {
         saveSetting("wfmAudioMode", nextMode);
       }
     }
+    if (wfmDenoiseEl && typeof update.filter.wfm_denoise === "boolean") {
+      if (wfmDenoiseEl.checked !== update.filter.wfm_denoise) {
+        wfmDenoiseEl.checked = update.filter.wfm_denoise;
+        saveSetting("wfmDenoise", update.filter.wfm_denoise ? "true" : "false");
+      }
+    }
     if (wfmStFlagEl && typeof update.filter.wfm_stereo_detected === "boolean") {
       const detected = update.filter.wfm_stereo_detected;
       wfmStFlagEl.textContent = detected ? "ST" : "MO";
@@ -2680,6 +2686,7 @@ const audioRow = document.getElementById("audio-row");
 const wfmControlsCol = document.getElementById("wfm-controls-col");
 const wfmDeemphasisEl = document.getElementById("wfm-deemphasis");
 const wfmAudioModeEl = document.getElementById("wfm-audio-mode");
+const wfmDenoiseEl = document.getElementById("wfm-denoise");
 const sdrGainControlsEl = document.getElementById("sdr-gain-controls");
 const sdrGainEl = document.getElementById("sdr-gain-db");
 const sdrGainSetBtn = document.getElementById("sdr-gain-set");
@@ -2748,6 +2755,14 @@ if (wfmAudioModeEl) {
     postPath(`/set_wfm_stereo?enabled=${enabled ? "true" : "false"}`).catch(() => {});
   });
 }
+if (wfmDenoiseEl) {
+  wfmDenoiseEl.checked = loadSetting("wfmDenoise", "true") === "true";
+  wfmDenoiseEl.addEventListener("change", () => {
+    const enabled = wfmDenoiseEl.checked;
+    saveSetting("wfmDenoise", enabled ? "true" : "false");
+    postPath(`/set_wfm_denoise?enabled=${enabled ? "true" : "false"}`).catch(() => {});
+  });
+}
 if (wfmDeemphasisEl) {
   wfmDeemphasisEl.addEventListener("change", () => {
     postPath(`/set_wfm_deemphasis?us=${encodeURIComponent(wfmDeemphasisEl.value)}`).catch(() => {});

src/trx-client/trx-frontend/trx-frontend-http/assets/web/index.html

@@ -172,6 +172,10 @@
                       <option value="mono">Mono</option>
                     </select>
                   </label>
+                  <label class="wfm-control">
+                    <span class="wfm-control-label">Denoise</span>
+                    <input type="checkbox" id="wfm-denoise" checked />
+                  </label>
                   <div class="wfm-gain-group" id="sdr-gain-controls">
                     <label class="wfm-control">
                       <span class="wfm-control-label">RF Gain</span>