feat: 实现数据库驱动的API配置管理和项目结构重组

## 新功能
- 实现管理后台API配置管理（OpenAI/Anthropic/Qwen）
- API配置保存到数据库，实时生效无需重启
- API密钥遮罩显示（前10位+后4位）
- 完整endpoint URL自动显示

## 后端改进
- 新增 config_service.py 用于加载数据库配置
- LLMService 支持动态配置注入，回退到环境变量
- 更新 exam.py 和 question.py 使用数据库配置
- 扩展 schemas.py 支持所有API配置字段

## 前端改进
- 重写 AdminSettings.jsx 增强UI体验
- API密钥显示/隐藏切换
- 当前使用的提供商可视化标识
- 移除"需要重启"的误导性提示

## 项目结构重组
- 移动所有脚本到 scripts/ 目录
- 移动所有文档到 docs/ 目录
- 清理 Python 缓存文件

🤖 Generated with Claude Code

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

frontend/src/pages/AdminSettings.jsx

@@ -1,21 +1,38 @@
 /**
- * Admin Settings Page
+ * Admin Settings Page - Enhanced with API Configuration
  */
 import React, { useState, useEffect } from 'react'
 import { adminAPI } from '../api/client'
 import { useAuth } from '../context/AuthContext'
-import { Settings, Save, Loader } from 'lucide-react'
+import { Settings, Save, Loader, Key, Link as LinkIcon, Eye, EyeOff } from 'lucide-react'
 import toast from 'react-hot-toast'
 
 export const AdminSettings = () => {
   const { user } = useAuth()
   const [loading, setLoading] = useState(true)
   const [saving, setSaving] = useState(false)
+  const [showApiKeys, setShowApiKeys] = useState({
+    openai: false,
+    anthropic: false,
+    qwen: false
+  })
+
   const [config, setConfig] = useState({
     allow_registration: true,
     max_upload_size_mb: 10,
     max_daily_uploads: 20,
-    ai_provider: 'openai'
+    ai_provider: 'openai',
+    // OpenAI
+    openai_api_key: '',
+    openai_base_url: 'https://api.openai.com/v1',
+    openai_model: 'gpt-4o-mini',
+    // Anthropic
+    anthropic_api_key: '',
+    anthropic_model: 'claude-3-haiku-20240307',
+    // Qwen
+    qwen_api_key: '',
+    qwen_base_url: 'https://dashscope.aliyuncs.com/compatible-mode/v1',
+    qwen_model: 'qwen-plus'
   })
 
   useEffect(() => {
@@ -54,6 +71,36 @@ export const AdminSettings = () => {
     })
   }
 
+  const toggleApiKeyVisibility = (provider) => {
+    setShowApiKeys({
+      ...showApiKeys,
+      [provider]: !showApiKeys[provider]
+    })
+  }
+
+  // Get complete API endpoint URL
+  const getCompleteEndpoint = (provider) => {
+    const endpoints = {
+      openai: '/chat/completions',
+      anthropic: '/messages',
+      qwen: '/chat/completions'
+    }
+
+    let baseUrl = ''
+    if (provider === 'openai') {
+      baseUrl = config.openai_base_url || 'https://api.openai.com/v1'
+    } else if (provider === 'anthropic') {
+      baseUrl = 'https://api.anthropic.com/v1'
+    } else if (provider === 'qwen') {
+      baseUrl = config.qwen_base_url || 'https://dashscope.aliyuncs.com/compatible-mode/v1'
+    }
+
+    // Remove trailing slash
+    baseUrl = baseUrl.replace(/\/$/, '')
+
+    return `${baseUrl}${endpoints[provider]}`
+  }
+
   if (loading) {
     return (
       <div className="min-h-screen bg-gray-100 flex items-center justify-center">
@@ -66,7 +113,7 @@ export const AdminSettings = () => {
     <div className="min-h-screen bg-gray-100">
       {/* Header */}
       <div className="bg-white shadow">
-        <div className="max-w-4xl mx-auto px-4 py-6">
+        <div className="max-w-5xl mx-auto px-4 py-6">
           <div className="flex items-center gap-3">
             <Settings className="h-8 w-8 text-primary-600" />
             <div>
@@ -78,8 +125,11 @@ export const AdminSettings = () => {
       </div>
 
       {/* Content */}
-      <div className="max-w-4xl mx-auto px-4 py-8">
+      <div className="max-w-5xl mx-auto px-4 py-8 space-y-6">
+        {/* Basic Settings */}
         <div className="bg-white rounded-xl shadow-md p-6 space-y-6">
+          <h2 className="text-xl font-bold text-gray-900 mb-4">基础设置</h2>
+
           {/* Allow Registration */}
           <div className="flex items-center justify-between">
             <div>
@@ -144,31 +194,244 @@ export const AdminSettings = () => {
               <option value="qwen">Qwen (通义千问)</option>
             </select>
             <p className="text-sm text-gray-500 mt-1">
-              需在 .env 文件中配置对应的 API Key
+              选择后在下方配置对应的 API 密钥
+            </p>
+          </div>
+        </div>
+
+        {/* OpenAI Configuration */}
+        <div className={`bg-white rounded-xl shadow-md p-6 space-y-4 ${config.ai_provider === 'openai' ? 'ring-2 ring-primary-500' : ''}`}>
+          <div className="flex items-center gap-2">
+            <Key className="h-5 w-5 text-green-600" />
+            <h2 className="text-xl font-bold text-gray-900">OpenAI 配置</h2>
+            {config.ai_provider === 'openai' && (
+              <span className="px-2 py-1 text-xs font-medium bg-primary-100 text-primary-700 rounded-full">当前使用</span>
+            )}
+          </div>
+
+          {/* API Key */}
+          <div>
+            <label className="block font-medium text-gray-900 mb-2">
+              API Key
+            </label>
+            <div className="relative">
+              <input
+                type={showApiKeys.openai ? 'text' : 'password'}
+                value={config.openai_api_key || ''}
+                onChange={(e) => handleChange('openai_api_key', e.target.value)}
+                placeholder="sk-proj-..."
+                className="w-full px-4 py-2 pr-10 border border-gray-300 rounded-lg focus:ring-2 focus:ring-primary-500 focus:border-transparent font-mono text-sm"
+              />
+              <button
+                type="button"
+                onClick={() => toggleApiKeyVisibility('openai')}
+                className="absolute right-3 top-1/2 -translate-y-1/2 text-gray-400 hover:text-gray-600"
+              >
+                {showApiKeys.openai ? <EyeOff className="h-5 w-5" /> : <Eye className="h-5 w-5" />}
+              </button>
+            </div>
+            <p className="text-sm text-gray-500 mt-1">从 https://platform.openai.com/api-keys 获取</p>
+          </div>
+
+          {/* Base URL */}
+          <div>
+            <label className="block font-medium text-gray-900 mb-2">
+              Base URL
+            </label>
+            <div className="relative">
+              <LinkIcon className="absolute left-3 top-1/2 -translate-y-1/2 h-5 w-5 text-gray-400" />
+              <input
+                type="text"
+                value={config.openai_base_url}
+                onChange={(e) => handleChange('openai_base_url', e.target.value)}
+                placeholder="https://api.openai.com/v1"
+                className="w-full pl-10 px-4 py-2 border border-gray-300 rounded-lg focus:ring-2 focus:ring-primary-500 focus:border-transparent font-mono text-sm"
+              />
+            </div>
+            <p className="text-xs text-gray-500 mt-1">
+              完整 endpoint: <code className="bg-gray-100 px-2 py-0.5 rounded">{getCompleteEndpoint('openai')}</code>
             </p>
           </div>
 
-          {/* Save Button */}
-          <div className="pt-4">
-            <button
-              onClick={handleSave}
-              disabled={saving}
-              className="w-full bg-primary-600 text-white py-3 rounded-lg font-medium hover:bg-primary-700 transition-colors disabled:opacity-50 disabled:cursor-not-allowed flex items-center justify-center gap-2"
+          {/* Model */}
+          <div>
+            <label className="block font-medium text-gray-900 mb-2">
+              模型
+            </label>
+            <select
+              value={config.openai_model}
+              onChange={(e) => handleChange('openai_model', e.target.value)}
+              className="w-full px-4 py-2 border border-gray-300 rounded-lg focus:ring-2 focus:ring-primary-500 focus:border-transparent"
             >
-              {saving ? (
-                <>
-                  <Loader className="h-5 w-5 animate-spin" />
-                  保存中...
-                </>
-              ) : (
-                <>
-                  <Save className="h-5 w-5" />
-                  保存设置
-                </>
-              )}
-            </button>
+              <option value="gpt-4o">gpt-4o (最强)</option>
+              <option value="gpt-4o-mini">gpt-4o-mini (推荐)</option>
+              <option value="gpt-4-turbo">gpt-4-turbo</option>
+              <option value="gpt-3.5-turbo">gpt-3.5-turbo</option>
+            </select>
           </div>
         </div>
+
+        {/* Anthropic Configuration */}
+        <div className={`bg-white rounded-xl shadow-md p-6 space-y-4 ${config.ai_provider === 'anthropic' ? 'ring-2 ring-primary-500' : ''}`}>
+          <div className="flex items-center gap-2">
+            <Key className="h-5 w-5 text-orange-600" />
+            <h2 className="text-xl font-bold text-gray-900">Anthropic 配置</h2>
+            {config.ai_provider === 'anthropic' && (
+              <span className="px-2 py-1 text-xs font-medium bg-primary-100 text-primary-700 rounded-full">当前使用</span>
+            )}
+          </div>
+
+          {/* API Key */}
+          <div>
+            <label className="block font-medium text-gray-900 mb-2">
+              API Key
+            </label>
+            <div className="relative">
+              <input
+                type={showApiKeys.anthropic ? 'text' : 'password'}
+                value={config.anthropic_api_key || ''}
+                onChange={(e) => handleChange('anthropic_api_key', e.target.value)}
+                placeholder="sk-ant-..."
+                className="w-full px-4 py-2 pr-10 border border-gray-300 rounded-lg focus:ring-2 focus:ring-primary-500 focus:border-transparent font-mono text-sm"
+              />
+              <button
+                type="button"
+                onClick={() => toggleApiKeyVisibility('anthropic')}
+                className="absolute right-3 top-1/2 -translate-y-1/2 text-gray-400 hover:text-gray-600"
+              >
+                {showApiKeys.anthropic ? <EyeOff className="h-5 w-5" /> : <Eye className="h-5 w-5" />}
+              </button>
+            </div>
+            <p className="text-sm text-gray-500 mt-1">从 https://console.anthropic.com/settings/keys 获取</p>
+          </div>
+
+          {/* Base URL (fixed for Anthropic) */}
+          <div>
+            <label className="block font-medium text-gray-900 mb-2">
+              Base URL (固定)
+            </label>
+            <div className="relative">
+              <LinkIcon className="absolute left-3 top-1/2 -translate-y-1/2 h-5 w-5 text-gray-400" />
+              <input
+                type="text"
+                value="https://api.anthropic.com/v1"
+                disabled
+                className="w-full pl-10 px-4 py-2 border border-gray-300 rounded-lg bg-gray-50 font-mono text-sm"
+              />
+            </div>
+            <p className="text-xs text-gray-500 mt-1">
+              完整 endpoint: <code className="bg-gray-100 px-2 py-0.5 rounded">{getCompleteEndpoint('anthropic')}</code>
+            </p>
+          </div>
+
+          {/* Model */}
+          <div>
+            <label className="block font-medium text-gray-900 mb-2">
+              模型
+            </label>
+            <select
+              value={config.anthropic_model}
+              onChange={(e) => handleChange('anthropic_model', e.target.value)}
+              className="w-full px-4 py-2 border border-gray-300 rounded-lg focus:ring-2 focus:ring-primary-500 focus:border-transparent"
+            >
+              <option value="claude-3-5-sonnet-20241022">claude-3-5-sonnet (最强)</option>
+              <option value="claude-3-haiku-20240307">claude-3-haiku (推荐)</option>
+              <option value="claude-3-opus-20240229">claude-3-opus</option>
+            </select>
+          </div>
+        </div>
+
+        {/* Qwen Configuration */}
+        <div className={`bg-white rounded-xl shadow-md p-6 space-y-4 ${config.ai_provider === 'qwen' ? 'ring-2 ring-primary-500' : ''}`}>
+          <div className="flex items-center gap-2">
+            <Key className="h-5 w-5 text-blue-600" />
+            <h2 className="text-xl font-bold text-gray-900">通义千问 配置</h2>
+            {config.ai_provider === 'qwen' && (
+              <span className="px-2 py-1 text-xs font-medium bg-primary-100 text-primary-700 rounded-full">当前使用</span>
+            )}
+          </div>
+
+          {/* API Key */}
+          <div>
+            <label className="block font-medium text-gray-900 mb-2">
+              API Key
+            </label>
+            <div className="relative">
+              <input
+                type={showApiKeys.qwen ? 'text' : 'password'}
+                value={config.qwen_api_key || ''}
+                onChange={(e) => handleChange('qwen_api_key', e.target.value)}
+                placeholder="sk-..."
+                className="w-full px-4 py-2 pr-10 border border-gray-300 rounded-lg focus:ring-2 focus:ring-primary-500 focus:border-transparent font-mono text-sm"
+              />
+              <button
+                type="button"
+                onClick={() => toggleApiKeyVisibility('qwen')}
+                className="absolute right-3 top-1/2 -translate-y-1/2 text-gray-400 hover:text-gray-600"
+              >
+                {showApiKeys.qwen ? <EyeOff className="h-5 w-5" /> : <Eye className="h-5 w-5" />}
+              </button>
+            </div>
+            <p className="text-sm text-gray-500 mt-1">从 https://dashscope.console.aliyun.com/apiKey 获取</p>
+          </div>
+
+          {/* Base URL */}
+          <div>
+            <label className="block font-medium text-gray-900 mb-2">
+              Base URL
+            </label>
+            <div className="relative">
+              <LinkIcon className="absolute left-3 top-1/2 -translate-y-1/2 h-5 w-5 text-gray-400" />
+              <input
+                type="text"
+                value={config.qwen_base_url}
+                onChange={(e) => handleChange('qwen_base_url', e.target.value)}
+                placeholder="https://dashscope.aliyuncs.com/compatible-mode/v1"
+                className="w-full pl-10 px-4 py-2 border border-gray-300 rounded-lg focus:ring-2 focus:ring-primary-500 focus:border-transparent font-mono text-sm"
+              />
+            </div>
+            <p className="text-xs text-gray-500 mt-1">
+              完整 endpoint: <code className="bg-gray-100 px-2 py-0.5 rounded">{getCompleteEndpoint('qwen')}</code>
+            </p>
+          </div>
+
+          {/* Model */}
+          <div>
+            <label className="block font-medium text-gray-900 mb-2">
+              模型
+            </label>
+            <select
+              value={config.qwen_model}
+              onChange={(e) => handleChange('qwen_model', e.target.value)}
+              className="w-full px-4 py-2 border border-gray-300 rounded-lg focus:ring-2 focus:ring-primary-500 focus:border-transparent"
+            >
+              <option value="qwen-max">qwen-max (最强)</option>
+              <option value="qwen-plus">qwen-plus (推荐)</option>
+              <option value="qwen-turbo">qwen-turbo</option>
+            </select>
+          </div>
+        </div>
+
+        {/* Save Button */}
+        <div className="bg-white rounded-xl shadow-md p-6">
+          <button
+            onClick={handleSave}
+            disabled={saving}
+            className="w-full bg-primary-600 text-white py-3 rounded-lg font-medium hover:bg-primary-700 transition-colors disabled:opacity-50 disabled:cursor-not-allowed flex items-center justify-center gap-2"
+          >
+            {saving ? (
+              <>
+                <Loader className="h-5 w-5 animate-spin" />
+                保存中...
+              </>
+            ) : (
+              <>
+                <Save className="h-5 w-5" />
+                保存所有设置
+              </>
+            )}
+          </button>
+        </div>
       </div>
     </div>
   )