🎉 Initial commit: QQuiz - 智能刷题与题库管理平台

## 功能特性

✅ **核心功能**
- 多文件上传与智能去重（基于 content_hash）
- 异步文档解析（支持 TXT/PDF/DOCX/XLSX）
- AI 智能题目提取与评分（OpenAI/Anthropic/Qwen）
- 断点续做与进度管理
- 自动错题本收集

✅ **技术栈**
- Backend: FastAPI + SQLAlchemy 2.0 + PostgreSQL
- Frontend: React 18 + Vite + Tailwind CSS
- Deployment: Docker Compose

✅ **项目结构**
- 53 个文件
- 完整的前后端分离架构
- Docker/源码双模部署支持

🚀 Generated with [Claude Code](https://claude.com/claude-code)

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

frontend/src/components/ProtectedRoute.jsx

@@ -0,0 +1,28 @@
+/**
+ * Protected Route Component
+ */
+import React from 'react'
+import { Navigate } from 'react-router-dom'
+import { useAuth } from '../context/AuthContext'
+
+export const ProtectedRoute = ({ children, adminOnly = false }) => {
+  const { user, loading } = useAuth()
+
+  if (loading) {
+    return (
+      <div className="min-h-screen flex items-center justify-center">
+        <div className="animate-spin rounded-full h-12 w-12 border-b-2 border-primary-600"></div>
+      </div>
+    )
+  }
+
+  if (!user) {
+    return <Navigate to="/login" replace />
+  }
+
+  if (adminOnly && !user.is_admin) {
+    return <Navigate to="/dashboard" replace />
+  }
+
+  return children
+}