fix: add groupName to ExecutionDetail, rewrite ExchangeDetail to match mock

- Add groupName field to ExecutionDetail record and DetailService
- Dashboard: fix TDZ error (rows referenced before definition), add
  selectedRow fallback for diagram groupName lookup
- ExchangeDetail: rewrite to match mock layout — auto-select first
  processor, Message IN/OUT split panels with header key-value rows,
  error panel for failed processors, Timeline/Flow toggle buttons
- Track diagram-mapping utility (was untracked, caused CI build failure)

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

ui/src/utils/diagram-mapping.ts

@@ -0,0 +1,55 @@
+import type { RouteNode } from '@cameleer/design-system';
+
+// Map NodeType strings to RouteNode types
+function mapNodeType(type: string): RouteNode['type'] {
+  const lower = type?.toLowerCase() || '';
+  if (lower.includes('from') || lower === 'endpoint') return 'from';
+  if (lower.includes('to')) return 'to';
+  if (lower.includes('choice') || lower.includes('when') || lower.includes('otherwise')) return 'choice';
+  if (lower.includes('error') || lower.includes('dead')) return 'error-handler';
+  return 'process';
+}
+
+function mapStatus(status: string | undefined): RouteNode['status'] {
+  if (!status) return 'ok';
+  const s = status.toUpperCase();
+  if (s === 'FAILED') return 'fail';
+  if (s === 'RUNNING') return 'slow';
+  return 'ok';
+}
+
+/**
+ * Maps diagram PositionedNodes + execution ProcessorNodes to RouteFlow RouteNode[] format.
+ * Joins on diagramNodeId → node.id.
+ */
+export function mapDiagramToRouteNodes(
+  diagramNodes: Array<{ id?: string; label?: string; type?: string }>,
+  processors: Array<{ diagramNodeId?: string; processorId?: string; status?: string; durationMs?: number; children?: any[] }>
+): RouteNode[] {
+  // Flatten processor tree
+  const flatProcessors: typeof processors = [];
+  function flatten(nodes: typeof processors) {
+    for (const n of nodes) {
+      flatProcessors.push(n);
+      if (n.children) flatten(n.children);
+    }
+  }
+  flatten(processors || []);
+
+  // Build lookup: diagramNodeId → processor
+  const procMap = new Map<string, (typeof flatProcessors)[0]>();
+  for (const p of flatProcessors) {
+    if (p.diagramNodeId) procMap.set(p.diagramNodeId, p);
+  }
+
+  return diagramNodes.map(node => {
+    const proc = procMap.get(node.id ?? '');
+    return {
+      name: node.label || node.id || '',
+      type: mapNodeType(node.type ?? ''),
+      durationMs: proc?.durationMs ?? 0,
+      status: mapStatus(proc?.status),
+      isBottleneck: false,
+    };
+  });
+}