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/preload.ts

@@ -8,5 +8,22 @@ window.addEventListener('DOMContentLoaded', () => {
 contextBridge.exposeInMainWorld('electronAPI', {
     openDevTools: () => ipcRenderer.invoke('open-dev-tools'),
     selectFolder: () => ipcRenderer.invoke('select-folder'),
-    selectFile: (filters?: any[]) => ipcRenderer.invoke('select-file', filters)
+    selectFile: (filters?: any[]) => ipcRenderer.invoke('select-file', filters),
+    
+    // 初始化相关API
+    checkEnvironment: () => ipcRenderer.invoke('check-environment'),
+    downloadPython: (mirror?: string) => ipcRenderer.invoke('download-python', mirror),
+    downloadGit: () => ipcRenderer.invoke('download-git'),
+    installDependencies: (mirror?: string) => ipcRenderer.invoke('install-dependencies', mirror),
+    cloneBackend: (repoUrl?: string) => ipcRenderer.invoke('clone-backend', repoUrl),
+    updateBackend: (repoUrl?: string) => ipcRenderer.invoke('update-backend', repoUrl),
+    startBackend: () => ipcRenderer.invoke('start-backend'),
+    
+    // 监听下载进度
+    onDownloadProgress: (callback: (progress: any) => void) => {
+        ipcRenderer.on('download-progress', (_, progress) => callback(progress))
+    },
+    removeDownloadProgressListener: () => {
+        ipcRenderer.removeAllListeners('download-progress')
+    }
 })