fix(sparking-cli): Fix spawn rspeedy ENOENT error when running npm run run:android on Windows

[JohnieXu]

Fixes #63

Summary

• Fix spawn rspeedy ENOENT error when running npm run run:android on Windows
• The issue occurs because sparkling-app-cli spawns rspeedy with shell: false, but on Windows, the rspeedy binary in node_modules/.bin is a Unix shell script that cannot be executed directly

Related issues

Fix #63

Changes

• exec.ts: Changed shell: false to shell: process.platform === 'win32' ? true : false so that Windows can properly execute batch files like gradlew.bat

How to test

1.create new project with npm create sparkling-app@latest
2.install deps
3.run npm run run:android

Checklist

• I read CONTRIBUTING.md.
• I linked a related issue (or explained why this is standalone).
• I ran relevant checks
• I updated docs/examples (if needed).
• I added/updated tests (if applicable), or explained why not.

[cla-assistant]

All committers have signed the CLA.

[leeekyrie]

@JohnieXu
We greatly appreciate your contribution, and this PR is very valuable to us. Per our project policy, you will need to sign the CLA before we can merge your code contribution. Once you complete the CLA signing, we will proceed to merge this PR.

我们很感激您的贡献，这个 PR 对我们来说非常重要。根据我们的政策，您为该项目贡献代码需要签署 CLA，完成签署之后我们将合入该 PR

[JohnieXu]

@leeekyrie CLA signed, please merge this.