fix(theme): close schema expansion popover on scroll

Repositioning the popover during scroll lagged behind the trigger and
felt detached. Close the popover instead so it always appears anchored
at the moment of opening. Also revert the tooltip text to its original
"Schema expansion depth".

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Author: sserrata

packages/docusaurus-theme-openapi-docs/src/theme/SchemaExpansion/index.tsx

@@ -66,10 +66,11 @@ const SchemaExpansionControl: React.FC = () => {
   useLayoutEffect(() => {
     if (!open) return;
     updatePosition();
-    window.addEventListener("scroll", updatePosition, true);
+    const handleScroll = () => setOpen(false);
+    window.addEventListener("scroll", handleScroll, true);
     window.addEventListener("resize", updatePosition);
     return () => {
-      window.removeEventListener("scroll", updatePosition, true);
+      window.removeEventListener("scroll", handleScroll, true);
       window.removeEventListener("resize", updatePosition);
     };
   }, [open, updatePosition]);
@@ -110,7 +111,7 @@ const SchemaExpansionControl: React.FC = () => {
   const levels = Array.from({ length: config.max + 1 }, (_, i) => i);
   const buttonLabel = translate({
     id: "theme.openapi.schema.expansion.button",
-    message: "Set how deep schemas auto-expand",
+    message: "Schema expansion depth",
     description: "Aria/title tooltip for the schema expansion icon button",
   });
   const allLabel = translate({