refactor: full SSR dashboard, minimal SSE DOM patches, poll-based refresh

apps/web/src/utils/sparkline.ts

@@ -0,0 +1,13 @@
+export function sparkline(values: number[], width = 120, height = 32): string {
+  if (!values.length) return '';
+  const max = Math.max(...values, 1);
+  const min = Math.min(...values, 0);
+  const range = max - min || 1;
+  const step = width / Math.max(values.length - 1, 1);
+  const points = values.map((v, i) => {
+    const x = i * step;
+    const y = height - ((v - min) / range) * (height - 4) - 2;
+    return `${x},${y}`;
+  }).join(' ');
+  return `<svg width="${width}" height="${height}" class="inline-block"><polyline points="${points}" fill="none" stroke="#60a5fa" stroke-width="1.5" stroke-linecap="round" stroke-linejoin="round"/></svg>`;
+}