fix(nav): the dead-page rewrite does not restore a spent focus stamp

It spread the event's snapshot, which still carried the sfNav stamp lib/history's own listener had
just taken off the entry, so a later landing there (an overlay closing) refocused a stale item. It
now spreads the live entry (test red on the snapshot). Also: format.test's comment named a test
image that never runs vitest; it is the gate host's locale.

frontend/src/components/NavigationProvider.tsx

@@ -200,11 +200,16 @@ export function NavigationProvider({ children }: { children: ReactNode }) {
       // An entry can name a page this build no longer has (one pushed before a module was removed,
       // reached by Back after a reload onto the new build); that lands on the feed, not on a crash.
       // The entry is rewritten to say so: left alone, the address bar would keep naming the dead page
-      // and a click on Feed would be a no-op (setPage's same-page guard).
+      // and a click on Feed would be a no-op (setPage's same-page guard). It spreads the LIVE entry,
+      // not `e.state`: lib/history's listener ran first and already took the spent `sfNav` off it.
       const sf: unknown = e.state?.sfPage;
       const p: Page = typeof sf === "string" && isPage(sf) ? sf : "feed";
       if (typeof sf === "string" && sf !== p)
-        window.history.replaceState({ ...e.state, sfPage: p }, "", urlWithParams({ page: null }));
+        window.history.replaceState(
+          { ...window.history.state, sfPage: p },
+          "",
+          urlWithParams({ page: null }),
+        );
       setPageState(p);
       setAccountRaw(PAGE_KEY, p);
       // The YouTube-search sub-view and the channel page ride in history.state, so Back/Forward