Persist GPU chart mode and expand GPU charts

audit/internal/webui/pages.go

@@ -553,6 +553,21 @@ func renderMetrics() string {
 
 <script>
 let gpuChartKey = '';
+const gpuChartModeStorageKey = 'bee.metrics.gpuChartMode';
+
+function loadGPUChartModePreference() {
+  try {
+    return sessionStorage.getItem(gpuChartModeStorageKey) === 'per-gpu';
+  } catch (_) {
+    return false;
+  }
+}
+
+function saveGPUChartModePreference(perGPU) {
+  try {
+    sessionStorage.setItem(gpuChartModeStorageKey, perGPU ? 'per-gpu' : 'per-metric');
+  } catch (_) {}
+}
 
 function refreshChartImage(el) {
   if (!el || el.dataset.loading === '1') return;
@@ -633,10 +648,19 @@ function loadMetricsLayout() {
   fetch('/api/metrics/latest').then(function(r) { return r.json(); }).then(syncMetricsLayout).catch(function() {});
 }
 
-document.getElementById('gpu-chart-toggle').addEventListener('change', function() {
-  applyGPUChartMode();
-  refreshCharts();
-});
+const gpuChartToggle = document.getElementById('gpu-chart-toggle');
+if (gpuChartToggle) {
+  gpuChartToggle.checked = loadGPUChartModePreference();
+}
+applyGPUChartMode();
+
+if (gpuChartToggle) {
+  gpuChartToggle.addEventListener('change', function() {
+    saveGPUChartModePreference(!!gpuChartToggle.checked);
+    applyGPUChartMode();
+    refreshCharts();
+  });
+}
 
 loadMetricsLayout();
 setInterval(refreshCharts, 3000);