feat: add Route Detail page with diagram, processor stats, and tabbed sections

Replaces the filtered RoutesMetrics view at /routes/:appId/:routeId with a
dedicated RouteDetail page showing route diagram, processor stats table,
performance charts, recent executions, and client-side grouped error patterns.

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

ui/src/api/queries/processor-metrics.ts

@@ -0,0 +1,25 @@
+import { useQuery } from '@tanstack/react-query';
+import { config } from '../../config';
+import { useAuthStore } from '../../auth/auth-store';
+
+export function useProcessorMetrics(routeId: string | null, appId?: string) {
+  return useQuery({
+    queryKey: ['processor-metrics', routeId, appId],
+    queryFn: async () => {
+      const token = useAuthStore.getState().accessToken;
+      const params = new URLSearchParams();
+      if (routeId) params.set('routeId', routeId);
+      if (appId) params.set('appId', appId);
+      const res = await fetch(`${config.apiBaseUrl}/routes/metrics/processors?${params}`, {
+        headers: {
+          Authorization: `Bearer ${token}`,
+          'X-Cameleer-Protocol-Version': '1',
+        },
+      });
+      if (!res.ok) throw new Error(`${res.status}`);
+      return res.json();
+    },
+    enabled: !!routeId,
+    refetchInterval: 30_000,
+  });
+}