修正競賽團隊編輯、個人賽顯示、團體賽顯示 bug

components/auth/profile-dialog.tsx

@@ -79,7 +79,7 @@ export function ProfileDialog({ open, onOpenChange }: ProfileDialogProps) {
           <div className="flex items-center space-x-6">
             <div className="relative">
               <Avatar className="w-24 h-24">
-                <AvatarImage src={user?.avatar || "/placeholder.svg"} />
+                <AvatarImage src={user?.avatar} />
                 <AvatarFallback className="text-2xl bg-gradient-to-r from-blue-600 to-purple-600 text-white">
                   {user?.name?.charAt(0) || "U"}
                 </AvatarFallback>