feat(ui): redesign ExchangeHeader with info bar, arrows, and navigation

- Always shows exchange info row: status dot, badge, ID, route, app, duration
- Correlation chain: arrow connectors between nodes, route name + duration per node
- Click on correlated exchange navigates to /exchanges/:app/:route/:exchangeId
- Compact styling with bg-raised background, proper visual hierarchy
- Horizontal scroll for long correlation chains

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

ui/src/pages/Exchanges/ExchangeHeader.tsx

@@ -1,3 +1,4 @@
+import { useNavigate } from 'react-router';
 import { StatusDot, MonoText, Badge } from '@cameleer/design-system';
 import { useCorrelationChain } from '../../api/queries/correlation';
 import type { ExecutionDetail } from '../../components/ExecutionDiagram/types';
@@ -5,7 +6,6 @@ import styles from './ExchangeHeader.module.css';
 
 interface ExchangeHeaderProps {
   detail: ExecutionDetail;
-  onExchangeClick?: (executionId: string) => void;
 }
 
 type StatusVariant = 'success' | 'error' | 'running' | 'warning';
@@ -19,25 +19,45 @@ function statusVariant(s: string): StatusVariant {
   }
 }
 
+function statusLabel(s: string): string {
+  switch (s) {
+    case 'COMPLETED': return 'OK';
+    case 'FAILED': return 'ERR';
+    case 'RUNNING': return 'RUN';
+    default: return s;
+  }
+}
+
 function formatDuration(ms: number): string {
   if (ms >= 60_000) return `${(ms / 1000).toFixed(0)}s`;
   if (ms >= 1000) return `${(ms / 1000).toFixed(2)}s`;
   return `${ms}ms`;
 }
 
-export function ExchangeHeader({ detail, onExchangeClick }: ExchangeHeaderProps) {
+export function ExchangeHeader({ detail }: ExchangeHeaderProps) {
+  const navigate = useNavigate();
   const { data: chainResult } = useCorrelationChain(detail.correlationId ?? null);
   const chain = chainResult?.data;
   const showChain = chain && chain.length > 1;
 
-  if (!showChain) return null;
-
   return (
     <div className={styles.header}>
+      {/* Exchange info — always shown */}
+      <div className={styles.info}>
+        <StatusDot variant={statusVariant(detail.status)} />
+        <Badge label={statusLabel(detail.status)} color={statusVariant(detail.status)} />
+        <MonoText size="xs">{(detail.exchangeId || detail.executionId).slice(0, 16)}</MonoText>
+        <span className={styles.separator} />
+        <span className={styles.route}>{detail.routeId}</span>
+        <span className={styles.app}>{detail.applicationName}</span>
+        <span className={styles.duration}>{formatDuration(detail.durationMs)}</span>
+      </div>
+
+      {/* Correlation chain — only when multiple correlated exchanges exist */}
       {showChain && (
         <div className={styles.chain}>
-          <span className={styles.chainLabel}>Correlated Exchanges</span>
-          {chain.map((ce: any) => {
+          <span className={styles.chainLabel}>Correlated</span>
+          {chain.map((ce: any, i: number) => {
             const isCurrent = ce.executionId === detail.executionId;
             const variant = statusVariant(ce.status);
             const statusCls =
@@ -46,15 +66,22 @@ export function ExchangeHeader({ detail, onExchangeClick }: ExchangeHeaderProps)
               : variant === 'running' ? styles.chainNodeRunning
               : styles.chainNodeWarning;
             return (
-              <button
-                key={ce.executionId}
-                className={`${styles.chainNode} ${statusCls} ${isCurrent ? styles.chainNodeCurrent : ''}`}
-                onClick={() => { if (!isCurrent) onExchangeClick?.(ce.executionId); }}
-                title={`${ce.executionId} \u2014 ${ce.routeId}`}
-              >
-                <StatusDot variant={variant} />
-                <span>{ce.routeId}</span>
-              </button>
+              <span key={ce.executionId} className={styles.chainEntry}>
+                {i > 0 && <span className={styles.chainArrow}>&rarr;</span>}
+                <button
+                  className={`${styles.chainNode} ${statusCls} ${isCurrent ? styles.chainNodeCurrent : ''}`}
+                  onClick={() => {
+                    if (!isCurrent) {
+                      navigate(`/exchanges/${ce.applicationName ?? detail.applicationName}/${ce.routeId}/${ce.executionId}`);
+                    }
+                  }}
+                  title={`${ce.executionId}\n${ce.routeId} \u2014 ${formatDuration(ce.durationMs)}`}
+                >
+                  <StatusDot variant={variant} />
+                  <span className={styles.chainRoute}>{ce.routeId}</span>
+                  <span className={styles.chainDuration}>{formatDuration(ce.durationMs)}</span>
+                </button>
+              </span>
             );
           })}
         </div>