fix: Restore sticky positioning on header wrapper div

apps/web/src/components/review/ReviewTab.tsx

@@ -325,7 +325,7 @@ export function ReviewTab({ initiativeId }: ReviewTabProps) {
   return (
     <div className="rounded-lg border border-border bg-card">
       {/* Header: phase selector + toolbar */}
-      <div ref={headerRef}>
+      <div ref={headerRef} className="sticky top-0 z-20">
       <ReviewHeader
         phases={reviewablePhases.map((p) => ({ id: p.id, name: p.name, status: p.status }))}
         activePhaseId={activePhaseId}