refactor: use vite for demo app

[gao-sun]

Summary

RIP parcel (i know the team's answer it's "not dead", but it's a duck death to us)

we loved parcel, bore its moodiness, but the latest version it can work properly stayed in 2.9.3, which released on Jun 25, 2023. after some research, i believe vite is the next cool kid's gear.

Testing

locally tested, sign-in/out demo app ok

Checklist

• [ ] .changeset (will update in a separate pull)
• [ ] unit tests
• [ ] integration tests
• [ ] necessary TSDoc comments

[github-actions[bot]]

COMPARE TO master

Total Size Diff :chart_with_upwards_trend: +1.5 KB

Diff by File

|Name|Diff| |---|---| |packages/core/src/middleware/koa-spa-proxy.ts|:chart_with_upwards_trend: +188 Bytes| |packages/demo-app/.parcelrc.arm64|:chart_with_upwards_trend: +185 Bytes| |packages/demo-app/index.html|:chart_with_upwards_trend: +419 Bytes| |packages/demo-app/package.json|:chart_with_upwards_trend: +443 Bytes| |packages/demo-app/src/index.html|:chart_with_upwards_trend: +415 Bytes| |packages/demo-app/tsconfig.json|:chart_with_upwards_trend: +18 Bytes| |packages/demo-app/vite.config.ts|:chart_with_upwards_trend: +931 Bytes| |pnpm-lock.yaml|:chart_with_upwards_trend: +1 KB|