Add route diagram page with execution overlay and group-aware APIs

Backend: Add group filtering to agent list, search, stats, and timeseries
endpoints. Add diagram lookup by group+routeId. Resolve application group
to agent IDs server-side for ClickHouse IN-clause queries.

Frontend: New route detail page at /apps/{group}/routes/{routeId} with
three tabs (Diagram, Performance, Processor Tree). SVG diagram rendering
with panzoom, execution overlay (glow effects, duration/sequence badges,
flow particles, minimap), and processor detail panel. uPlot charts for
performance tab replacing old SVG sparklines. Ctrl+Click from
ExecutionExplorer navigates to route diagram with overlay.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ui/src/components/charts/ThroughputChart.tsx

@@ -0,0 +1,57 @@
+import { useRef, useEffect } from 'react';
+import uPlot from 'uplot';
+import 'uplot/dist/uPlot.min.css';
+import { baseOpts, chartColors } from './theme';
+import type { TimeseriesBucket } from '../../api/types';
+
+interface ThroughputChartProps {
+  buckets: TimeseriesBucket[];
+}
+
+export function ThroughputChart({ buckets }: ThroughputChartProps) {
+  const containerRef = useRef<HTMLDivElement>(null);
+  const chartRef = useRef<uPlot | null>(null);
+
+  useEffect(() => {
+    if (!containerRef.current || buckets.length < 2) return;
+    const el = containerRef.current;
+    const w = el.clientWidth || 600;
+
+    const xs = buckets.map((b) => new Date(b.time!).getTime() / 1000);
+    const totals = buckets.map((b) => b.totalCount ?? 0);
+    const failed = buckets.map((b) => b.failedCount ?? 0);
+
+    const opts: uPlot.Options = {
+      ...baseOpts(w, 220),
+      width: w,
+      height: 220,
+      series: [
+        { label: 'Time' },
+        {
+          label: 'Total',
+          stroke: chartColors.amber,
+          fill: `${chartColors.amber}20`,
+          width: 2,
+        },
+        {
+          label: 'Failed',
+          stroke: chartColors.rose,
+          fill: `${chartColors.rose}20`,
+          width: 2,
+        },
+      ],
+    };
+
+    chartRef.current?.destroy();
+    chartRef.current = new uPlot(opts, [xs, totals, failed], el);
+
+    return () => {
+      chartRef.current?.destroy();
+      chartRef.current = null;
+    };
+  }, [buckets]);
+
+  if (buckets.length < 2) return null;
+
+  return <div ref={containerRef} />;
+}