feat: initialize Ballet Island 微信小程序 with basic structure and functionality

- Add project configuration for WeChat mini program.
- Create skills lock file for Taroify integration.
- Set up app configuration and styles.
- Implement main app component and index page with welcome message.
- Add health check service to verify backend readiness.
- Configure TypeScript settings and global types.

miniprogram/src/app.tsx

@@ -0,0 +1,7 @@
+import type { PropsWithChildren } from 'react'
+import './app.scss'
+
+export default function App({ children }: PropsWithChildren) {
+  return children
+}
+