fix(web): center active filters and compact mobile cards

reaction_board/web/static/components.js

@@ -127,6 +127,15 @@ export function metricChips(metrics, active, dataName = "metric") {
   )).join("");
 }
 
+export function centerActiveChips(root) {
+  root.querySelectorAll(".chip-row.scroll-x").forEach((row) => {
+    const active = row.querySelector(".chip.active");
+    if (!active) return;
+    const target = active.offsetLeft - row.clientWidth / 2 + active.clientWidth / 2;
+    row.scrollLeft = Math.max(0, target);
+  });
+}
+
 export function pager(page, pages) {
   if (!pages || pages <= 1) return "";
   return `<div class="pager">