Add Playwright smoke test for core editor functionality

[sanchit955]

Summary

Adds a minimal Playwright E2E smoke test to validate core editor functionality.

Changes

• Added Playwright setup and configuration

• Implemented a basic smoke test for:

  • Editor load
  • Play button interaction

• Uses stable selector (#play-sketch)

• Validates preview trigger via iframe visibility

Why

This establishes a foundation for future E2E testing and helps prevent regressions in core editor workflows.

Notes

• Avoided fragile checks (e.g., canvas detection) due to dynamic iframe behavior
• Focused on stable user-visible signals instead

How to Run

npm install
npx playwright install
npm run test:e2e

[sanchit955]

Refined the E2E test to focus on a stable smoke test for the Play flow.

Avoided fragile iframe/canvas checks and instead validated the preview trigger via iframe visibility.

Happy to expand coverage based on feedback.