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.

config/prod.ts

@@ -1,4 +1,5 @@
-import type { UserConfigExport } from "@tarojs/cli";
+import type { UserConfigExport } from "@tarojs/cli"
+
 export default {
   mini: {},
   h5: {
@@ -29,4 +30,4 @@ export default {
     //     }))
     // }
   }
-} satisfies UserConfigExport<'vite'>
+} satisfies UserConfigExport<'webpack5'>