feat: update project configuration and structure

- Updated project.config.json with new project name and settings.
- Removed unused app.scss and index.scss files, replaced with CSS files.
- Refactored app.ts to utilize Taro's useLaunch hook for app initialization.
- Simplified index.tsx to display a basic greeting and user info button.
- Added new project.xhs.json for XHS platform configuration.
- Introduced is-xhs utility function to check for XHS environment.
- Updated tsconfig.json to include path mappings and additional include paths.

tsconfig.json

@@ -13,15 +13,18 @@
     "noUnusedParameters": true,
     "strictNullChecks": true,
     "sourceMap": true,
-    "baseUrl": ".",
     "rootDir": ".",
     "jsx": "react-jsx",
     "allowJs": true,
     "resolveJsonModule": true,
     "typeRoots": [
       "node_modules/@types"
-    ]
+    ],
+    "paths": {
+      // TS5090 leading './'
+      "@/*": ["./src/*"]
+    }
   },
-  "include": ["./src", "./types"],
+  "include": ["./src", "./types", "./config"],
   "compileOnSave": false
 }