fix: auto-reload on chunk load errors in ErrorBoundary

RouteError already handled stale chunk errors, but the Sentry ErrorBoundary
didn't — so errors from React lazy() imports hit the generic error UI.
Now auto-reloads with loop prevention (10s cooldown via sessionStorage).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/src/components/common/ErrorBoundary.tsx

@@ -7,7 +7,29 @@ interface FallbackProps {
   resetError: () => void
 }
 
+function isChunkLoadError(error: Error): boolean {
+  const msg = error.message || ''
+  return (
+    msg.includes('dynamically imported module') ||
+    msg.includes('Loading chunk') ||
+    msg.includes('Failed to fetch') ||
+    error.name === 'ChunkLoadError'
+  )
+}
+
 function DefaultFallback({ error, resetError }: FallbackProps) {
+  // Auto-reload on stale chunk errors (happens after deployments)
+  if (isChunkLoadError(error)) {
+    const key = 'rf_boundary_chunk_reload'
+    const lastReload = sessionStorage.getItem(key)
+    const now = Date.now()
+    if (!lastReload || now - Number(lastReload) > 10_000) {
+      sessionStorage.setItem(key, String(now))
+      window.location.reload()
+      return null
+    }
+  }
+
   return (
     <div className="flex min-h-[400px] flex-col items-center justify-center p-8">
       <div className="max-w-md text-center">