Fix the App Router race that occurs when a user presses Back after a reloaded document has committed but before hydration has installed the router's history listener. Once hydration completes, the rendered route and the browser's current history entry must be reconciled, including entries that differ by pathname or only by search parameters, and subsequent Back/Forward navigation must continue to keep URL and content in sync. Recovery must work both with and without a Suspense boundary above the page and must not cause a full-page reload. Preserve existing behavior for pre-hydration third-party pushState writes, in-page hash navigation, and traversals involving non-App-Router history entries; these must not be mistaken for a missed framework traversal, and the router must remain usable afterward.