fix: theme-aware chart colors — readable axes and tooltips in light mode

site/src/components/MmpChart.svelte

@@ -82,6 +82,10 @@
 
   $: colorMap = Object.fromEntries(selectedKeys.map((k, i) => [k, curveColor(k, i)]));
 
+  function getAxisColor() {
+    return document.documentElement.getAttribute('data-theme') === 'light' ? '#52525b' : '#a1a1aa';
+  }
+
   function renderChart(data: typeof plotData, cmap: typeof colorMap) {
     if (!chartEl) return;
     chartEl.innerHTML = '';
@@ -95,7 +99,7 @@
       height: 320,
       marginLeft: 52,
       marginBottom: 40,
-      style: { background: 'transparent', color: '#e4e4e7' },
+      style: { background: 'transparent', color: getAxisColor() },
       x: {
         type: 'log',
         label: 'Duration',
@@ -160,7 +164,9 @@
   onMount(() => {
     const ro = new ResizeObserver(() => renderChart(currentPlotData, currentColorMap));
     ro.observe(chartEl);
-    return () => ro.disconnect();
+    const mo = new MutationObserver(() => renderChart(currentPlotData, currentColorMap));
+    mo.observe(document.documentElement, { attributes: true, attributeFilter: ['data-theme'] });
+    return () => { ro.disconnect(); mo.disconnect(); };
   });
 
   // ── Toggle helpers ─────────────────────────────────────────────────────────