fix(landing-nav): use popstate timestamp window so flag self-expires

Author: waleedlatif1

apps/sim/app/(landing)/components/scroll-to-top.tsx

@@ -4,16 +4,21 @@ import { useEffect } from 'react'
 import { usePathname } from 'next/navigation'
 
 /**
- * Module-level flag so the popstate signal survives layout remounts when the
- * user navigates across sections (e.g., blog ↔ integrations ↔ models), where
- * the outgoing layout — and its component instances — unmount before the
- * incoming layout's effect runs.
+ * Timestamp of the most recent popstate. Module-scoped so it survives layout
+ * remounts when navigating across sections (e.g., blog ↔ integrations ↔ models),
+ * where the outgoing layout's component instances unmount before the incoming
+ * layout's effect runs.
+ *
+ * A timestamp window (rather than a sticky boolean) self-expires the signal —
+ * a hash-only back/forward fires popstate but doesn't change `usePathname`, so
+ * a boolean would never be consumed and would poison the next real navigation.
  */
-let isPopNavigation = false
+let lastPopstateAt = 0
+const POPSTATE_WINDOW_MS = 200
 
 if (typeof window !== 'undefined') {
   window.addEventListener('popstate', () => {
-    isPopNavigation = true
+    lastPopstateAt = performance.now()
   })
 }
 
@@ -23,18 +28,15 @@ if (typeof window !== 'undefined') {
  * Next.js's default scroll handling only brings the new Page element into view,
  * which often resolves to "no scroll" inside shared layouts (see vercel/next.js#64435).
  *
- * Popstate-driven navigations are skipped so browser back/forward scroll
- * restoration is preserved, and hash-anchor navigations are skipped so the
- * browser's native anchor scroll wins.
+ * Skipped when the pathname change closely follows a popstate (preserving browser
+ * back/forward scroll restoration) or when a hash anchor is targeted (letting the
+ * browser's native anchor scroll win).
  */
 export function ScrollToTop() {
   const pathname = usePathname()
 
   useEffect(() => {
-    if (isPopNavigation) {
-      isPopNavigation = false
-      return
-    }
+    if (performance.now() - lastPopstateAt < POPSTATE_WINDOW_MS) return
     if (window.location.hash) return
     window.scrollTo(0, 0)
   }, [pathname])