[feat](trx-client): support virtual channel bandwidth control

Add client-side command plumbing, HTTP endpoint handling, and frontend interception so bandwidth changes are applied per active virtual channel and survive reconnects.

Co-authored-by: OpenAI Codex <codex@openai.com>
Signed-off-by: Stan Grams <sjg@haxx.space>

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

@@ -3278,6 +3278,7 @@ async function applyBandwidthFromInput() {
   syncBandwidthInput(clamped);
   if (lastSpectrumData) scheduleSpectrumDraw();
   try {
+    if (typeof vchanInterceptBandwidth === "function" && await vchanInterceptBandwidth(clamped)) return;
     await postPath(`/set_bandwidth?hz=${clamped}`);
     if (Number.isFinite(lastFreqHz)) {
       await ensureTunedBandwidthCoverage(lastFreqHz);
@@ -3352,6 +3353,7 @@ async function applyAutoBandwidth() {
   syncBandwidthInput(estimated);
   if (lastSpectrumData) scheduleSpectrumDraw();
   try {
+    if (typeof vchanInterceptBandwidth === "function" && await vchanInterceptBandwidth(estimated)) return;
     await postPath(`/set_bandwidth?hz=${estimated}`);
     if (Number.isFinite(lastFreqHz)) {
       await ensureTunedBandwidthCoverage(lastFreqHz);
@@ -7774,9 +7776,12 @@ if (spectrumCanvas || overviewCanvas) {
   window.addEventListener("mouseup", async () => {
     if (_bwDragEdge) {
       try {
-        await postPath(`/set_bandwidth?hz=${Math.round(currentBandwidthHz)}`);
-        if (Number.isFinite(lastFreqHz)) {
-          await ensureTunedBandwidthCoverage(lastFreqHz, currentBandwidthHz);
+        const bwHz = Math.round(currentBandwidthHz);
+        if (!(typeof vchanInterceptBandwidth === "function" && await vchanInterceptBandwidth(bwHz))) {
+          await postPath(`/set_bandwidth?hz=${bwHz}`);
+          if (Number.isFinite(lastFreqHz)) {
+            await ensureTunedBandwidthCoverage(lastFreqHz, currentBandwidthHz);
+          }
         }
       } catch (_) {}
       _bwDragEdge = null;

src/trx-client/trx-frontend/trx-frontend-http/assets/web/plugins/bookmarks.js

@@ -286,10 +286,17 @@ async function bmApply(bm) {
       modeEl.value = String(bm.mode || "").toUpperCase();
     }
     if (bm.bandwidth_hz) {
-      await postPath("/set_bandwidth?hz=" + bm.bandwidth_hz);
+      const bwHandledByVchan = typeof vchanInterceptBandwidth === "function"
+        && await vchanInterceptBandwidth(bm.bandwidth_hz);
+      if (!bwHandledByVchan) {
+        await postPath("/set_bandwidth?hz=" + bm.bandwidth_hz);
+      }
       if (typeof currentBandwidthHz !== "undefined") {
         currentBandwidthHz = bm.bandwidth_hz;
       }
+      if (typeof window !== "undefined") {
+        window.currentBandwidthHz = bm.bandwidth_hz;
+      }
       if (typeof syncBandwidthInput === "function") {
         syncBandwidthInput(bm.bandwidth_hz);
       }

src/trx-client/trx-frontend/trx-frontend-http/assets/web/plugins/vchan.js

@@ -236,6 +236,29 @@ function vchanSyncModeDisplay() {
   // When on primary channel, app.js rig-state updates handle the picker.
 }
 
+// Sync the BW input to the active virtual channel's bandwidth.
+function vchanSyncBwDisplay() {
+  if (!vchanIsOnVirtual()) return;
+  const ch = vchanActiveChannel();
+  if (!ch) return;
+  const bwEl = document.getElementById("spectrum-bw-input");
+  if (!bwEl) return;
+  // bandwidth_hz == 0 means mode-default; derive it from the channel mode.
+  let bwHz = ch.bandwidth_hz || 0;
+  if (bwHz === 0 && typeof mwDefaultsForMode === "function") {
+    bwHz = mwDefaultsForMode(ch.mode)[0] || 0;
+  }
+  if (bwHz > 0) {
+    bwEl.value = (bwHz / 1000).toFixed(3).replace(/\.?0+$/, "");
+    if (typeof currentBandwidthHz !== "undefined") {
+      currentBandwidthHz = bwHz;
+      window.currentBandwidthHz = bwHz;
+    } else {
+      window.currentBandwidthHz = bwHz;
+    }
+  }
+}
+
 // Add / remove the vchan accent class from the freq and BW inputs.
 function vchanSyncAccentUI() {
   const onVirtual = vchanIsOnVirtual();
@@ -246,6 +269,7 @@ function vchanSyncAccentUI() {
   if (onVirtual) {
     vchanUpdateFreqDisplay();
     vchanSyncModeDisplay();
+    vchanSyncBwDisplay();
   } else if (typeof _origRefreshFreqDisplay === "function") {
     _origRefreshFreqDisplay();
   }
@@ -286,6 +310,23 @@ async function vchanSetChannelFreq(freqHz) {
   }
 }
 
+async function vchanSetChannelBandwidth(bwHz) {
+  if (!vchanRigId || !vchanActiveId) return;
+  try {
+    const resp = await fetch(
+      `/channels/${encodeURIComponent(vchanRigId)}/${encodeURIComponent(vchanActiveId)}/bw`,
+      {
+        method: "PUT",
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify({ bandwidth_hz: Math.round(bwHz) }),
+      }
+    );
+    if (!resp.ok) console.warn("vchan: set bw failed", resp.status);
+  } catch (e) {
+    console.error("vchan: set bw error", e);
+  }
+}
+
 async function vchanSetChannelMode(mode) {
   if (!vchanRigId || !vchanActiveId) return;
   try {
@@ -312,6 +353,14 @@ window.vchanInterceptMode = async function(mode) {
   return true;
 };
 
+// Called by app.js bandwidth setters before sending /set_bandwidth to the
+// server.  Returns true if the change was handled by the virtual channel.
+window.vchanInterceptBandwidth = async function(bwHz) {
+  if (!vchanIsOnVirtual()) return false;
+  await vchanSetChannelBandwidth(bwHz);
+  return true;
+};
+
 // Wrap setRigFrequency (defined in app.js, loaded before this file) so that
 // frequency changes are redirected to the active virtual channel instead of
 // the server when on a non-primary channel.