feat(initialization): 添加初始化页面和相关功能

- 新增初始化页面组件和路由
- 实现环境检查、Git下载、后端代码克隆等功能
- 添加下载服务和环境服务模块
- 更新类型定义，增加 Electron API 接口

frontend/electron/services/environmentService.ts

@@ -0,0 +1,35 @@
+import * as path from 'path'
+import * as fs from 'fs'
+import { app } from 'electron'
+
+// 获取应用根目录
+export function getAppRoot(): string {
+  return process.env.NODE_ENV === 'development' 
+    ? process.cwd() 
+    : path.dirname(app.getPath('exe'))
+}
+
+// 检查环境
+export function checkEnvironment(appRoot: string) {
+  const environmentPath = path.join(appRoot, 'environment')
+  const pythonPath = path.join(environmentPath, 'python')
+  const gitPath = path.join(environmentPath, 'git')
+  const backendPath = path.join(appRoot, 'backend')
+  const requirementsPath = path.join(backendPath, 'requirements.txt')
+
+  const pythonExists = fs.existsSync(pythonPath)
+  const gitExists = fs.existsSync(gitPath)
+  const backendExists = fs.existsSync(backendPath)
+  
+  // 检查依赖是否已安装（简单检查是否存在site-packages目录）
+  const sitePackagesPath = path.join(pythonPath, 'Lib', 'site-packages')
+  const dependenciesInstalled = fs.existsSync(sitePackagesPath) && fs.readdirSync(sitePackagesPath).length > 10
+
+  return {
+    pythonExists,
+    gitExists,
+    backendExists,
+    dependenciesInstalled,
+    isInitialized: pythonExists && gitExists && backendExists && dependenciesInstalled
+  }
+}