Stabilize sweep progress updates

static/js/modes/listening-post.js

@@ -15,7 +15,6 @@ let scannerCycles = 0;
 let scannerStartFreq = 118;
 let scannerEndFreq = 137;
 let scannerSignalActive = false;
-let lastScanFreq = null;
 
 // Audio state
 let isAudioPlaying = false;
@@ -182,7 +181,6 @@ function startScanner() {
     scannerEndFreq = endFreq;
     scannerFreqsScanned = 0;
     scannerCycles = 0;
-    lastScanFreq = null;
 
     // Update sidebar display
     updateScannerDisplay('STARTING...', 'var(--accent-orange)');
@@ -296,7 +294,6 @@ function stopScanner() {
             isScannerPaused = false;
             scannerSignalActive = false;
             currentSignalLevel = 0;
-            lastScanFreq = null;
 
             // Re-enable listen button (will be in local mode after stop)
             updateListenButtonState(false);
@@ -575,18 +572,6 @@ function handleScannerEvent(data) {
 function handleFrequencyUpdate(data) {
     const freqStr = data.frequency.toFixed(3);
 
-    // Prevent jitter from out-of-order sweep segments
-    if (lastScanFreq !== null) {
-        const range = scannerEndFreq - scannerStartFreq;
-        if (range > 0 && data.frequency < lastScanFreq) {
-            const drop = lastScanFreq - data.frequency;
-            if (drop < range * 0.5) {
-                return; // ignore backward blip within sweep
-            }
-        }
-    }
-    lastScanFreq = data.frequency;
-
     const currentFreq = document.getElementById('scannerCurrentFreq');
     if (currentFreq) currentFreq.textContent = freqStr + ' MHz';
 
@@ -594,7 +579,9 @@ function handleFrequencyUpdate(data) {
     if (mainFreq) mainFreq.textContent = freqStr;
 
     // Update progress bar
-    const progress = ((data.frequency - scannerStartFreq) / (scannerEndFreq - scannerStartFreq)) * 100;
+    const progress = (data.progress !== undefined)
+        ? (data.progress * 100)
+        : ((data.frequency - scannerStartFreq) / (scannerEndFreq - scannerStartFreq)) * 100;
     const progressBar = document.getElementById('scannerProgressBar');
     if (progressBar) progressBar.style.width = Math.max(0, Math.min(100, progress)) + '%';