feat: show replay marker on correlated chain entries

Exchanges with a _replay attribute now display a small amber
RotateCcw icon between the status dot and route name in the
correlation chain. Tooltip also indicates (replay).

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

ui/src/pages/Exchanges/ExchangeHeader.tsx

@@ -1,6 +1,6 @@
 import { useMemo } from 'react';
 import { useNavigate } from 'react-router';
-import { GitBranch, Server } from 'lucide-react';
+import { GitBranch, Server, RotateCcw } from 'lucide-react';
 import { StatusDot, MonoText, Badge } from '@cameleer/design-system';
 import { useCorrelationChain } from '../../api/queries/correlation';
 import { useAgents } from '../../api/queries/agents';
@@ -122,6 +122,7 @@ export function ExchangeHeader({ detail, onCorrelatedSelect, onClearSelection }:
         {showChain ? chain.map((ce: any, i: number) => {
             const isCurrent = ce.executionId === detail.executionId;
             const variant = statusVariant(ce.status);
+            const isReplay = ce.attributes?._replay != null;
             const statusCls =
               variant === 'success' ? styles.chainNodeSuccess
               : variant === 'error' ? styles.chainNodeError
@@ -137,9 +138,10 @@ export function ExchangeHeader({ detail, onCorrelatedSelect, onClearSelection }:
                       onCorrelatedSelect(ce.executionId, ce.applicationName ?? detail.applicationName, ce.routeId);
                     }
                   }}
-                  title={`${ce.executionId}\n${ce.routeId} \u2014 ${formatDuration(ce.durationMs)}`}
+                  title={`${ce.executionId}\n${ce.routeId} \u2014 ${formatDuration(ce.durationMs)}${isReplay ? '\n(replay)' : ''}`}
                 >
                   <StatusDot variant={variant} />
+                  {isReplay && <RotateCcw size={9} className={styles.replayIcon} />}
                   <span className={styles.chainRoute}>{ce.routeId}</span>
                   <span className={styles.chainDuration}>{formatDuration(ce.durationMs)}</span>
                 </button>