add images for chatting room title

src/components/InstructorChatPanel.tsx

@@ -222,7 +222,7 @@ function ThreadCard({ thread, onOpen }: { thread: InstructorChatThread; onOpen:
   );
 }
 
-function StudentAvatar({ thread }: { thread: InstructorChatThread }) {
+function StudentAvatar({ thread, size = 'md' }: { thread: InstructorChatThread; size?: 'sm' | 'md' }) {
   const [avatarFailed, setAvatarFailed] = useState(false);
 
   useEffect(() => {
@@ -230,7 +230,7 @@ function StudentAvatar({ thread }: { thread: InstructorChatThread }) {
   }, [thread.studentAvatarUrl]);
 
   return (
-    <span className="grid h-10 w-10 shrink-0 place-items-center overflow-hidden rounded-full bg-[#eef2ff] text-[#4f46e5] transition group-hover:bg-[#4f46e5] group-hover:text-white">
+    <span className={`${size === 'sm' ? 'h-9 w-9' : 'h-10 w-10'} grid shrink-0 place-items-center overflow-hidden rounded-full bg-[#eef2ff] text-[#4f46e5] transition group-hover:bg-[#4f46e5] group-hover:text-white`}>
       {thread.studentAvatarUrl && !avatarFailed ? (
         <img className="h-full w-full object-cover" src={thread.studentAvatarUrl} alt="" onError={() => setAvatarFailed(true)} />
       ) : (
@@ -291,6 +291,7 @@ function ChatRoom({
         <button className="grid h-9 w-9 place-items-center rounded-md text-[#64748b] hover:bg-[#f8fafc] hover:text-[#111827]" type="button" aria-label="목록으로 돌아가기" title="목록으로 돌아가기" onClick={onBack}>
           <ArrowLeft size={17} aria-hidden="true" />
         </button>
+        <StudentAvatar thread={thread} size="sm" />
         <div className="min-w-0 flex-1">
           <div className="flex items-center gap-2">
             <p className="truncate text-[15px] font-black text-[#0f172a]">{thread.studentName}</p>