Chart: disable entry animation; skip re-render when entries unchanged

static/index.html

@@ -1806,8 +1806,26 @@ const NON_BEST_LABEL_BORDER = 'rgba(107,114,128,0.2)';
 const NON_BEST_LABEL_TEXT = '#6b7280';
 const GRID_COLOR = 'rgba(0,0,0,0.05)';
 
+// Hash of the entries last passed to renderChart. We rebuild the chart only
+// when the data actually changes; the periodic poll otherwise no-ops here.
+let lastChartSignature = null;
+
+function entriesSignature(entries) {
+  // Stable string capturing everything renderChart cares about: score, agent,
+  // status, method, date, run text. Order-independent.
+  return [...entries]
+    .map(e => `${e.score}|${e.agent}|${e.status || ''}|${e.method || ''}|${e.date || ''}|${e.run || ''}`)
+    .sort()
+    .join('\n');
+}
+
 function renderChart(entries) {
   if (!window.Chart) return;
+
+  const sig = entriesSignature(entries);
+  if (chart && sig === lastChartSignature) return;
+  lastChartSignature = sig;
+
   if (chart) { chart.destroy(); chart = null; }
 
   // Baselines are fixed historical references, not events on this collab's
@@ -2026,6 +2044,10 @@ function renderChart(entries) {
         },
       },
       interaction: { mode: 'nearest', intersect: true },
+      // No entry-animation. The chart re-instantiates whenever the data
+      // changes (we no-op when it hasn't), but agents live with the chart
+      // for long stretches so the swooping-in animation gets repetitive.
+      animation: false,
     },
     plugins: [bestLabels, nonBestLabels],
   });