docs(app): clarify RootLayout scroll-reset comment

scrollRestoration only affects POP navigation, not PUSH/REPLACE. The
real reason for window.scrollTo(0, 0) is that SPA route transitions
inherently keep the previous scroll position. Update the comment to
state that, and stop singling out PlotsPage since HomePage also sets
scrollRestoration.

Author: claude

app/src/components/RootLayout.tsx

@@ -27,12 +27,12 @@ export function RootLayout() {
   const navigationType = useNavigationType();
   const mastheadSticks = pathname !== '/plots';
 
-  // Reset scroll on forward navigation (PUSH/REPLACE). Without this, short
-  // pages like /legal inherit the previous page's scroll position because
-  // PlotsPage sets scrollRestoration='manual'. Skip on POP so browser
-  // back/forward keeps native scroll restoration; skip when a hash anchor
-  // is present so in-page anchors still work. PlotsPage runs its own
-  // saved-scroll restore in a later effect, so it still overrides this.
+  // Reset scroll on forward navigation (PUSH/REPLACE). In SPA route changes,
+  // the next page can otherwise keep the previous page's scroll position,
+  // which is especially noticeable on short pages like /legal. Skip on POP
+  // so browser back/forward keeps native scroll restoration; skip when a
+  // hash anchor is present so in-page anchors still work. Pages with their
+  // own saved-scroll restore in a later effect can still override this.
   useEffect(() => {
     if (hash) return;
     if (navigationType === 'POP') return;