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/skills-lock.json

@@ -0,0 +1,10 @@
+{
+  "version": 1,
+  "skills": {
+    "taroify": {
+      "source": "./node_modules/@taroify/cli/skills/taroify",
+      "sourceType": "local",
+      "computedHash": "c1a0f9254edcf2d10ba8d0d6373cbb14a29bf054c8683e5a5855d37aa692b1b8"
+    }
+  }
+}