fix: constructor mismatch breaking waveforms, restore clock, hide ECG/Pleth strips until real data arrives

- WaveformTrack was being called with old (baseline, amplitude) args
  instead of new (mode) string, breaking all normalization
- Clock function was accidentally removed in a prior edit
- ECG and Pleth strips now hidden by default and only appear when
  the monitor actually sends waveform data for that channel
- Resp strip always visible (synthetic from RR value)

fiveparaminte-main/static/dashboard.html

@@ -159,6 +159,14 @@ body{
   background:rgba(0,0,0,0.7);pointer-events:none;z-index:3;
 }
 
+/* ── No data overlay on strip ── */
+.strip-nodata{
+  position:absolute;inset:0;z-index:4;
+  display:flex;align-items:center;justify-content:center;
+  font-size:12px;color:#2a4a2a;letter-spacing:1px;
+  pointer-events:none;
+}
+
 /* ── Minimal mode ── */
 body.minimal-mode #statusBar{display:none;}
 body.minimal-mode #monitorBody{height:100vh;}
@@ -192,12 +200,14 @@ body.minimal-mode #monitorBody{height:100vh;}
 
   <!-- Waveform strips -->
   <div id="waveformCol">
-    <div class="waveform-strip" id="strip-ecg">
+    <div class="waveform-strip" id="strip-ecg" style="display:none;">
       <div class="strip-label ecg">I ECG</div>
+      <div class="strip-nodata" id="nodata-ecg">Waiting for ECG lead data…</div>
       <canvas class="strip-canvas" id="canvas-ecg"></canvas>
     </div>
-    <div class="waveform-strip" id="strip-pleth">
+    <div class="waveform-strip" id="strip-pleth" style="display:none;">
       <div class="strip-label pleth">PLETH</div>
+      <div class="strip-nodata" id="nodata-pleth">Waiting for SpO₂ probe…</div>
       <canvas class="strip-canvas" id="canvas-pleth"></canvas>
     </div>
     <div class="waveform-strip" id="strip-resp">
@@ -259,6 +269,17 @@ const isDemo = params.get('demo') === 'true' || params.get('synth') === 'true';
 
 if (isMinimal) document.body.classList.add('minimal-mode');
 
+// ════════════════════════════════════════════════════
+//  CLOCK
+// ════════════════════════════════════════════════════
+function updateClock(){
+  const n = new Date();
+  document.getElementById('clockDisplay').textContent =
+    n.toLocaleTimeString('en-GB',{hour12:false});
+}
+setInterval(updateClock, 1000);
+updateClock();
+
 // ════════════════════════════════════════════════════
 //  CANVAS WAVEFORM ENGINE
 //  Continuous right-to-left scrolling sweep
@@ -434,15 +455,22 @@ class WaveformTrack {
 }
 
 // ════════════════════════════════════════════════════
-//  TRACKS
+//  TRACKS (mode must match constructor: 'ecg' | 'pleth' | 'resp')
 // ════════════════════════════════════════════════════
-const ecgTrack   = new WaveformTrack('canvas-ecg',  '#00ff41', 0.5, 0.42);
-const plethTrack = new WaveformTrack('canvas-pleth','#00e5ff', 0.5, 0.38);
-const respTrack  = new WaveformTrack('canvas-resp', '#ffb300', 0.5, 0.30);
+const ecgTrack   = new WaveformTrack('canvas-ecg',  '#00ff41', 'ecg');
+const plethTrack = new WaveformTrack('canvas-pleth','#00e5ff', 'pleth');
+const respTrack  = new WaveformTrack('canvas-resp', '#ffb300', 'resp');
 
-ecgTrack.synthType   = 'ecg';
-plethTrack.synthType = 'pleth';
-respTrack.synthType  = 'resp';
+// Track whether real data has been received (to show/hide strips)
+let ecgActive  = false;
+let plethActive = false;
+
+function showStrip(id, nodataId) {
+  const strip = document.getElementById(id);
+  const nd    = document.getElementById(nodataId);
+  if (strip) strip.style.display = '';
+  if (nd)    nd.style.display = 'none';
+}
 
 // Resize observer
 const ro = new ResizeObserver(() => {
@@ -455,9 +483,13 @@ const TICKS_PER_FRAME = 3; // speed of sweep
 function loop() {
   ecgTrack.resize(); plethTrack.resize(); respTrack.resize();
   for (let i=0;i<TICKS_PER_FRAME;i++){
-    ecgTrack.tick(); plethTrack.tick(); respTrack.tick();
+    if (ecgActive)  ecgTrack.tick();
+    if (plethActive) plethTrack.tick();
+    respTrack.tick();
   }
-  ecgTrack.draw(); plethTrack.draw(); respTrack.draw();
+  if (ecgActive)  ecgTrack.draw();
+  if (plethActive) plethTrack.draw();
+  respTrack.draw();
   requestAnimationFrame(loop);
 }
 requestAnimationFrame(loop);
@@ -600,9 +632,15 @@ function connectWS() {
       // Filter by device if known
       if (deviceId && d.device_id && d.device_id !== deviceId) return;
 
-      // Push waveform samples if present
-      if (d.ecg_wave   && d.ecg_wave.length)   ecgTrack.pushSamples(d.ecg_wave);
-      if (d.pleth_wave && d.pleth_wave.length) plethTrack.pushSamples(d.pleth_wave);
+      // Push waveform samples if present — show strip on first real data
+      if (d.ecg_wave && d.ecg_wave.length) {
+        if (!ecgActive) { ecgActive = true; showStrip('strip-ecg', 'nodata-ecg'); }
+        ecgTrack.pushSamples(d.ecg_wave);
+      }
+      if (d.pleth_wave && d.pleth_wave.length) {
+        if (!plethActive) { plethActive = true; showStrip('strip-pleth', 'nodata-pleth'); }
+        plethTrack.pushSamples(d.pleth_wave);
+      }
 
       // Update numeric params
       updateParams(d);