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/tsconfig.app.json

@@ -0,0 +1,12 @@
+{
+  "extends": "@vue/tsconfig/tsconfig.dom.json",
+  "include": ["env.d.ts", "src/**/*", "src/**/*.vue"],
+  "exclude": ["src/**/__tests__/*"],
+  "compilerOptions": {
+    "tsBuildInfoFile": "./node_modules/.tmp/tsconfig.app.tsbuildinfo",
+
+    "paths": {
+      "@/*": ["./src/*"]
+    }
+  }
+}