feat(app): add thinking model support

src/components/ThinkBox.tsx

@@ -0,0 +1,43 @@
+'use client';
+
+import { useState } from 'react';
+import { cn } from '@/lib/utils';
+import { ChevronDown, ChevronUp, BrainCircuit } from 'lucide-react';
+
+interface ThinkBoxProps {
+  content: string;
+}
+
+const ThinkBox = ({ content }: ThinkBoxProps) => {
+  const [isExpanded, setIsExpanded] = useState(false);
+
+  return (
+    <div className="my-4 bg-light-secondary/50 dark:bg-dark-secondary/50 rounded-xl border border-light-200 dark:border-dark-200 overflow-hidden">
+      <button
+        onClick={() => setIsExpanded(!isExpanded)}
+        className="w-full flex items-center justify-between px-4 py-1 text-black/90 dark:text-white/90 hover:bg-light-200 dark:hover:bg-dark-200 transition duration-200"
+      >
+        <div className="flex items-center space-x-2">
+          <BrainCircuit
+            size={20}
+            className="text-[#9C27B0] dark:text-[#CE93D8]"
+          />
+          <p className="font-medium text-sm">Thinking Process</p>
+        </div>
+        {isExpanded ? (
+          <ChevronUp size={18} className="text-black/70 dark:text-white/70" />
+        ) : (
+          <ChevronDown size={18} className="text-black/70 dark:text-white/70" />
+        )}
+      </button>
+
+      {isExpanded && (
+        <div className="px-4 py-3 text-black/80 dark:text-white/80 text-sm border-t border-light-200 dark:border-dark-200 bg-light-100/50 dark:bg-dark-100/50 whitespace-pre-wrap">
+          {content}
+        </div>
+      )}
+    </div>
+  );
+};
+
+export default ThinkBox;