fix: use diagramContentHash for Route Flow instead of groupName

The deployed backend doesn't return groupName on ExecutionDetail or
ExecutionSummary (Docker build cache issue). Switch diagram lookup to
use diagramContentHash which is always available in the detail response.

- Dashboard: useDiagramLayout(detail.diagramContentHash) instead of
  useDiagramByRoute(groupName, routeId)
- ExchangeDetail: same change

Route Flow now renders correctly in both the slide-in panel and the
full exchange detail page.

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

ui/src/pages/Dashboard/Dashboard.tsx

@@ -7,7 +7,7 @@ import {
 } from '@cameleer/design-system';
 import type { Column } from '@cameleer/design-system';
 import { useSearchExecutions, useExecutionStats, useStatsTimeseries, useExecutionDetail } from '../../api/queries/executions';
-import { useDiagramByRoute } from '../../api/queries/diagrams';
+import { useDiagramLayout } from '../../api/queries/diagrams';
 import { useGlobalFilters } from '@cameleer/design-system';
 import type { ExecutionSummary } from '../../api/types';
 import { mapDiagramToRouteNodes } from '../../utils/diagram-mapping';
@@ -46,8 +46,7 @@ export default function Dashboard() {
     [searchResult],
   );
 
-  const selectedRow = rows.find(r => r.id === selectedId);
-  const { data: diagram } = useDiagramByRoute(detail?.groupName ?? selectedRow?.groupName, detail?.routeId);
+  const { data: diagram } = useDiagramLayout(detail?.diagramContentHash ?? null);
 
   const totalCount = stats?.totalCount ?? 0;
   const failedCount = stats?.failedCount ?? 0;

ui/src/pages/ExchangeDetail/ExchangeDetail.tsx

@@ -6,7 +6,7 @@ import {
 } from '@cameleer/design-system';
 import { useExecutionDetail, useProcessorSnapshot } from '../../api/queries/executions';
 import { useCorrelationChain } from '../../api/queries/correlation';
-import { useDiagramByRoute } from '../../api/queries/diagrams';
+import { useDiagramLayout } from '../../api/queries/diagrams';
 import { mapDiagramToRouteNodes } from '../../utils/diagram-mapping';
 import styles from './ExchangeDetail.module.css';
 
@@ -41,7 +41,7 @@ export default function ExchangeDetail() {
   const { data: detail, isLoading } = useExecutionDetail(id ?? null);
   const [timelineView, setTimelineView] = useState<'gantt' | 'flow'>('gantt');
   const { data: correlationData } = useCorrelationChain(detail?.correlationId ?? null);
-  const { data: diagram } = useDiagramByRoute(detail?.groupName, detail?.routeId);
+  const { data: diagram } = useDiagramLayout(detail?.diagramContentHash ?? null);
 
   const procList = detail ? (detail.processors?.length ? detail.processors : (detail.children ?? [])) : [];