feat(webui): combined GPU charts (load/memload/power/temp all GPUs per chart)

Replace per-GPU cards with 4 combined charts showing all GPUs as
separate series. Add gpu-all-load/memload/power/temp endpoints.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

audit/internal/webui/pages.go

@@ -392,12 +392,6 @@ func renderMetrics() string {
   </div>
 </div>
 
-<div class="card" style="margin-bottom:16px">
-  <div class="card-head">Temperature — GPUs</div>
-  <div class="card-body" style="padding:8px">
-    <img id="chart-server-temp-gpu" src="/api/metrics/chart/server-temp-gpu.svg" style="width:100%;display:block;border-radius:6px" alt="GPU temperature">
-  </div>
-</div>
 
 <div class="card" style="margin-bottom:16px">
   <div class="card-head">Temperature — Ambient Sensors</div>
@@ -421,50 +415,47 @@ func renderMetrics() string {
   </div>
 </div>
 
-<div id="gpu-charts"></div>
+<div class="card" style="margin-bottom:16px">
+  <div class="card-head">GPU — Compute Load</div>
+  <div class="card-body" style="padding:8px">
+    <img id="chart-gpu-all-load" src="/api/metrics/chart/gpu-all-load.svg" style="width:100%;display:block;border-radius:6px" alt="GPU compute load">
+  </div>
+</div>
+<div class="card" style="margin-bottom:16px">
+  <div class="card-head">GPU — Memory Load</div>
+  <div class="card-body" style="padding:8px">
+    <img id="chart-gpu-all-memload" src="/api/metrics/chart/gpu-all-memload.svg" style="width:100%;display:block;border-radius:6px" alt="GPU memory load">
+  </div>
+</div>
+<div class="card" style="margin-bottom:16px">
+  <div class="card-head">GPU — Power</div>
+  <div class="card-body" style="padding:8px">
+    <img id="chart-gpu-all-power" src="/api/metrics/chart/gpu-all-power.svg" style="width:100%;display:block;border-radius:6px" alt="GPU power">
+  </div>
+</div>
+<div class="card" style="margin-bottom:16px">
+  <div class="card-head">GPU — Temperature</div>
+  <div class="card-body" style="padding:8px">
+    <img id="chart-gpu-all-temp" src="/api/metrics/chart/gpu-all-temp.svg" style="width:100%;display:block;border-radius:6px" alt="GPU temperature">
+    <div id="gpu-table" style="margin-top:8px;font-size:12px"></div>
+  </div>
+</div>
 
 <script>
-let knownGPUs = [];
-
 function refreshCharts() {
   const t = '?t=' + Date.now();
-  ['chart-server-load','chart-server-temp-cpu','chart-server-temp-gpu','chart-server-temp-ambient','chart-server-power','chart-server-fans'].forEach(id => {
+  ['chart-server-load','chart-server-temp-cpu','chart-server-temp-gpu','chart-server-temp-ambient','chart-server-power','chart-server-fans',
+   'chart-gpu-all-load','chart-gpu-all-memload','chart-gpu-all-power','chart-gpu-all-temp'].forEach(id => {
     const el = document.getElementById(id);
     if (el) el.src = el.src.split('?')[0] + t;
   });
-  knownGPUs.forEach(idx => {
-    ['load','power'].forEach(kind => {
-      const el = document.getElementById('chart-gpu-' + idx + '-' + kind);
-      if (el) el.src = el.src.split('?')[0] + t;
-    });
-  });
 }
-setInterval(refreshCharts, 2000);
+setInterval(refreshCharts, 3000);
 
 const es = new EventSource('/api/metrics/stream');
 es.addEventListener('metrics', e => {
   const d = JSON.parse(e.data);
 
-  // Add GPU chart cards as GPUs appear
-  (d.gpus||[]).forEach(g => {
-    if (knownGPUs.includes(g.index)) return;
-    knownGPUs.push(g.index);
-    const div = document.createElement('div');
-    div.className = 'card';
-    div.style.marginBottom = '16px';
-    div.innerHTML =
-      '<div class="card-head">GPU ' + g.index + ' — Load</div>' +
-      '<div class="card-body" style="padding:8px">' +
-        '<img id="chart-gpu-' + g.index + '-load" src="/api/metrics/chart/gpu/' + g.index + '-load.svg" style="width:100%;display:block;border-radius:6px" alt="GPU ' + g.index + ' load">' +
-      '</div>' +
-      '<div class="card-head">GPU ' + g.index + ' — Power</div>' +
-      '<div class="card-body" style="padding:8px">' +
-        '<img id="chart-gpu-' + g.index + '-power" src="/api/metrics/chart/gpu/' + g.index + '-power.svg" style="width:100%;display:block;border-radius:6px" alt="GPU ' + g.index + ' power">' +
-        '<div id="gpu-table-' + g.index + '" style="margin-top:8px;font-size:12px"></div>' +
-      '</div>';
-    document.getElementById('gpu-charts').appendChild(div);
-  });
-
   // Update numeric tables
   let sysHTML = '';
   (d.temps||[]).filter(t => t.group === 'cpu').forEach(t => {
@@ -477,15 +468,16 @@ es.addEventListener('metrics', e => {
   const st = document.getElementById('sys-table');
   if (st) st.innerHTML = sysHTML ? '<table>'+sysHTML+'</table>' : '<p style="color:var(--muted)">No sensor data (ipmitool/sensors required)</p>';
 
+  let gpuHTML = '';
   (d.gpus||[]).forEach(g => {
-    const t = document.getElementById('gpu-table-' + g.index);
+    gpuHTML += '<tr><td>GPU '+g.index+'</td>' +
-    if (!t) return;
+      '<td>'+g.temp_c+'°C</td>' +
-    t.innerHTML = '<table>' +
+      '<td>'+g.usage_pct+'% load</td>' +
-      '<tr><td>Temp</td><td>'+g.temp_c+'°C</td>' +
+      '<td>'+g.mem_usage_pct+'% mem</td>' +
-      '<td>Load</td><td>'+g.usage_pct+'%</td>' +
+      '<td>'+g.power_w+' W</td></tr>';
-      '<td>Mem</td><td>'+g.mem_usage_pct+'%</td>' +
-      '<td>Power</td><td>'+g.power_w+' W</td></tr></table>';
   });
+  const gt = document.getElementById('gpu-table');
+  if (gt) gt.innerHTML = gpuHTML ? '<table>'+gpuHTML+'</table>' : '';
 });
 es.onerror = () => {};
 </script>`

audit/internal/webui/server.go

@@ -449,7 +449,80 @@ func (h *handler) handleMetricsChartSVG(w http.ResponseWriter, r *http.Request)
 		yMin = floatPtr(0)
 		yMax = autoMax120(datasets...)
 
-	// ── GPU sub-charts ────────────────────────────────────────────────────
+	// ── Combined GPU charts (all GPUs on one chart) ───────────────────────
+	case path == "gpu-all-load":
+		title = "GPU Compute Load"
+		h.ringsMu.Lock()
+		for idx, gr := range h.gpuRings {
+			if gr == nil {
+				continue
+			}
+			vUtil, l := gr.Util.snapshot()
+			datasets = append(datasets, vUtil)
+			names = append(names, fmt.Sprintf("GPU %d %%", idx))
+			if len(labels) == 0 {
+				labels = l
+			}
+		}
+		h.ringsMu.Unlock()
+		yMin = floatPtr(0)
+		yMax = floatPtr(100)
+
+	case path == "gpu-all-memload":
+		title = "GPU Memory Load"
+		h.ringsMu.Lock()
+		for idx, gr := range h.gpuRings {
+			if gr == nil {
+				continue
+			}
+			vMem, l := gr.MemUtil.snapshot()
+			datasets = append(datasets, vMem)
+			names = append(names, fmt.Sprintf("GPU %d %%", idx))
+			if len(labels) == 0 {
+				labels = l
+			}
+		}
+		h.ringsMu.Unlock()
+		yMin = floatPtr(0)
+		yMax = floatPtr(100)
+
+	case path == "gpu-all-power":
+		title = "GPU Power"
+		h.ringsMu.Lock()
+		for idx, gr := range h.gpuRings {
+			if gr == nil {
+				continue
+			}
+			vPow, l := gr.Power.snapshot()
+			datasets = append(datasets, vPow)
+			names = append(names, fmt.Sprintf("GPU %d W", idx))
+			if len(labels) == 0 {
+				labels = l
+			}
+		}
+		h.ringsMu.Unlock()
+		yMin = floatPtr(0)
+		yMax = autoMax120(datasets...)
+
+	case path == "gpu-all-temp":
+		title = "GPU Temperature"
+		h.ringsMu.Lock()
+		for idx, gr := range h.gpuRings {
+			if gr == nil {
+				continue
+			}
+			vTemp, l := gr.Temp.snapshot()
+			datasets = append(datasets, vTemp)
+			names = append(names, fmt.Sprintf("GPU %d °C", idx))
+			if len(labels) == 0 {
+				labels = l
+			}
+		}
+		h.ringsMu.Unlock()
+		yMin = floatPtr(0)
+		yMax = autoMax120(datasets...)
+
+	// ── Per-GPU sub-charts ────────────────────────────────────────────────
 	case strings.HasPrefix(path, "gpu/"):
 		rest := strings.TrimPrefix(path, "gpu/")
 		// rest is either "{idx}-load", "{idx}-temp", "{idx}-power", or legacy "{idx}"