docs: 添加中文文档，新增前端和后端代码

- 新增 README_CN.md 中文文档
- 新增 frontend/ Vue 3 前端项目
- 新增 web/ FastAPI 后端项目

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

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

frontend/vite.config.ts

@@ -0,0 +1,30 @@
+import { fileURLToPath, URL } from 'node:url'
+
+import { defineConfig } from 'vite'
+import vue from '@vitejs/plugin-vue'
+import vueDevTools from 'vite-plugin-vue-devtools'
+import AutoImport from 'unplugin-auto-import/vite'
+import Components from 'unplugin-vue-components/vite'
+import { ElementPlusResolver } from 'unplugin-vue-components/resolvers'
+
+// https://vite.dev/config/
+export default defineConfig({
+  plugins: [
+    vue(),
+    vueDevTools(),
+    AutoImport({
+      resolvers: [ElementPlusResolver()],
+      imports: ['vue', 'vue-router'],
+      dts: 'src/auto-imports.d.ts',
+    }),
+    Components({
+      resolvers: [ElementPlusResolver()],
+      dts: 'src/components.d.ts',
+    }),
+  ],
+  resolve: {
+    alias: {
+      '@': fileURLToPath(new URL('./src', import.meta.url))
+    },
+  },
+})