Add minimum height to library ask thread tab wrapper

- Add `min-h-12` to the root tab container in `library-ask-thread-tabs.tsx`
- Prevents the tabs strip from collapsing vertically and stabilizes layout

Author: EricTsai83

src/components/library-ask-thread-tabs.tsx

@@ -57,7 +57,7 @@ export const LibraryAskThreadTabs = memo(function LibraryAskThreadTabs({
   const prewarmThread = usePrewarmThread();
 
   return (
-    <div className={cn("relative flex items-center border-b border-border bg-background", className)}>
+    <div className={cn("relative flex min-h-12 items-center border-b border-border bg-background", className)}>
       <ScrollArea className="min-w-0 flex-1">
         <ul
           role="tablist"