refactor: extract duplicated utility functions into shared format-utils

Consolidate formatDuration, statusToVariant, statusLabel, formatTimestamp,
toRouteNodeType, and durationClass from 5 page/component files into one
shared utils module.

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

src/pages/ExchangeDetail/ExchangeDetail.tsx

@@ -18,6 +18,9 @@ import { MonoText } from '../../design-system/primitives/MonoText/MonoText'
 import { CodeBlock } from '../../design-system/primitives/CodeBlock/CodeBlock'
 import { InfoCallout } from '../../design-system/primitives/InfoCallout/InfoCallout'
 
+// Utils
+import { formatDuration, statusToVariant, toRouteNodeType } from '../../utils/format-utils'
+
 // Mock data
 import { exchanges } from '../../mocks/exchanges'
 import { buildRouteToAppMap } from '../../mocks/sidebar'
@@ -25,21 +28,6 @@ import { buildRouteToAppMap } from '../../mocks/sidebar'
 const ROUTE_TO_APP = buildRouteToAppMap()
 
 // ─── Helpers ──────────────────────────────────────────────────────────────────
-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`
-}
-
-function statusToVariant(status: 'completed' | 'failed' | 'running' | 'warning'): 'success' | 'error' | 'running' | 'warning' {
-  switch (status) {
-    case 'completed': return 'success'
-    case 'failed': return 'error'
-    case 'running': return 'running'
-    case 'warning': return 'warning'
-  }
-}
-
 function statusToLabel(status: 'completed' | 'failed' | 'running' | 'warning'): string {
   switch (status) {
     case 'completed': return 'COMPLETED'
@@ -145,16 +133,6 @@ function generateExchangeSnapshotOut(
   }
 }
 
-// Map processor types to RouteNode types
-function toRouteNodeType(procType: string): RouteNode['type'] {
-  switch (procType) {
-    case 'consumer': return 'from'
-    case 'transform': return 'process'
-    case 'enrich': return 'process'
-    default: return procType as RouteNode['type']
-  }
-}
-
 // ─── ExchangeDetail component ─────────────────────────────────────────────────
 export function ExchangeDetail() {
   const { id } = useParams<{ id: string }>()