feat(web): /search two-pane screen (debounced query, visibility filter, load more) + nav

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

web/src/search/select-search-prompt.tsx

@@ -0,0 +1,11 @@
+import { useTranslation } from "react-i18next";
+
+export function SelectSearchPrompt() {
+  const { t } = useTranslation();
+
+  return (
+    <div className="flex h-full items-center justify-center p-4 text-sm text-neutral-400">
+      {t("search.selectPrompt")}
+    </div>
+  );
+}