fix(web): avoid skeleton flicker and cache overview while filtering

reaction_board/web/static/router.js

@@ -136,8 +136,11 @@ async function render(options = {}) {
   if (scrollTop && !preserveScroll) {
     window.scrollTo({ top: 0, behavior: "auto" });
   }
-  routeElement.innerHTML = `<div class="page-loading"><div class="skeleton skeleton-title"></div>
-    <div class="skeleton skeleton-card"></div><div class="skeleton skeleton-card"></div></div>`;
+  if (!preserveScroll) {
+    // 保留滚动位置的原地更新不要插入骨架屏，否则列表会短暂消失、滚动条闪烁。
+    routeElement.innerHTML = `<div class="page-loading"><div class="skeleton skeleton-title"></div>
+      <div class="skeleton skeleton-card"></div><div class="skeleton skeleton-card"></div></div>`;
+  }
   try {
     await matched.route.view(routeElement, {
       params: matched.match.slice(1),