feat: 完成前端项目初始化 (TASK-003)

- 创建 Next.js 14+ 前端项目，TypeScript + Tailwind CSS
- 安装核心依赖：axios, react-hook-form, zod, zustand, recharts
- 安装 Shadcn/ui 组件库
- 配置环境变量和基础目录结构
- 验证构建成功

任务状态：TASK-003 已完成
下一步：TASK-004 配置数据库

Assisted-by: Kiro AI <kiro@cursor.com>

frontend/.gitignore

@@ -0,0 +1,41 @@
+# See https://help.github.com/articles/ignoring-files/ for more about ignoring files.
+
+# dependencies
+/node_modules
+/.pnp
+.pnp.*
+.yarn/*
+!.yarn/patches
+!.yarn/plugins
+!.yarn/releases
+!.yarn/versions
+
+# testing
+/coverage
+
+# next.js
+/.next/
+/out/
+
+# production
+/build
+
+# misc
+.DS_Store
+*.pem
+
+# debug
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+.pnpm-debug.log*
+
+# env files (can opt-in for committing if needed)
+.env*
+
+# vercel
+.vercel
+
+# typescript
+*.tsbuildinfo
+next-env.d.ts