fix(landing-nav): hoist popstate flag to module scope and skip on hash anchors

Author: waleedlatif1

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

@@ -1,33 +1,41 @@
 'use client'
 
-import { useEffect, useRef } from 'react'
+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.
+ */
+let isPopNavigation = false
+
+if (typeof window !== 'undefined') {
+  window.addEventListener('popstate', () => {
+    isPopNavigation = true
+  })
+}
+
 /**
  * Resets window scroll to the top on App Router pathname changes.
  *
  * 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.
+ *
+ * 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.
  */
 export function ScrollToTop() {
   const pathname = usePathname()
-  const isPopNavigationRef = useRef(false)
-
-  useEffect(() => {
-    const onPop = () => {
-      isPopNavigationRef.current = true
-    }
-    window.addEventListener('popstate', onPop)
-    return () => window.removeEventListener('popstate', onPop)
-  }, [])
 
   useEffect(() => {
-    if (isPopNavigationRef.current) {
-      isPopNavigationRef.current = false
+    if (isPopNavigation) {
+      isPopNavigation = false
       return
     }
+    if (window.location.hash) return
     window.scrollTo(0, 0)
   }, [pathname])