feat(deeplink): jump from banner/rank list to the exact post in All Materials

- FigmaBanner: route same-app linkUrl through SPA navigation so the stream's
  scroll-to-post runs without a full reload; defer pointer capture until a real
  drag starts, fixing plain clicks being swallowed by setPointerCapture
- PopularRankList: rank rows navigate straight to /browse?sort=popular&post=<id>
- MessageStream: ?post= deep links jump directly to the target instead of
  resetting to the top and animating through the stream
- ScrollToTop: skip the top-reset for ?post= navigations so the target page
  handles its own alignment

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/components/ScrollToTop.tsx

@@ -7,14 +7,14 @@ import { useLocation } from "react-router-dom";
  * clamp to wherever the previous (taller) page was scrolled — e.g. landing at
  * the bottom of a category page after clicking a card far down the home grid.
  *
- * Skips navigations that carry a hash (`#post-<id>`, `#categories`, …) so
- * anchor / deep-link targets keep their own scroll handling.
+ * Skips navigations that carry a hash (`#post-<id>`, `#categories`, …) or a
+ * `?post=<id>` deep link so the target page can handle its own alignment.
  */
 export function ScrollToTop() {
   const { pathname, search, hash } = useLocation();
 
   useEffect(() => {
-    if (hash) return;
+    if (hash || new URLSearchParams(search).has("post")) return;
     window.scrollTo({ top: 0, left: 0 });
   }, [pathname, search, hash]);