fix: peak0c scope bug and strt cross check fix

sfm/waveform_viewer.html

@@ -527,6 +527,10 @@
         ? samples.slice(0, displayCount)
         : samples;
 
+      // peak0C declared here (function scope) so it is visible in the Chart.js
+      // config block below (which lives outside the if(isGeo) block).
+      let peak0C = null;
+
       if (isGeo) {
         // Geo channels: counts × (range / 32767) → in/s
         // Scale factor for the waveform shape (may need calibration per unit)
@@ -535,7 +539,7 @@
 
         // Use the device-computed 0C record peak for the label (authoritative).
         // The raw-sample-computed peak can be inflated by frame-boundary artifacts.
-        const peak0C = peakValues0C[ch];
+        peak0C = peakValues0C[ch];
         const peakIns = (peak0C !== null && peak0C !== undefined)
           ? peak0C
           : Math.max(...plotSamples.map(Math.abs));