新增功能：初始化时下载python和git

ui/src/pages/Init.vue

@@ -1,13 +1,16 @@
 <script setup>
 const steps = ref([
-  { title: '设置 Git LFS', command: ['lfs'] },
+  {
+    title: '下载 git、python',
+    command: ['download_git', 'download_python']
+  },
   {
     title: '安装 pip',
     command: ['ensurepip']
   },
   {
     title: '下载 mower-ng 代码',
-    command: ['clone']
+    command: ['lfs', 'clone']
   }
 ])
 provide('steps', steps)