Add deploy-preview workflow for PR CI/CD

[mangit955]

Summary

This PR adds a GitHub Actions workflow (deploy-preview.yml) to prepare the project for automated CI/CD previews on pull requests, along with a separate test workflow to validate its configuration.

Changes Introduced

1. Deploy Preview Workflow (.github/workflows/deploy-preview.yml)

   • Runs on pull requests to main.
   • Installs root and client dependencies.
   • Builds the client application.
   • Includes a Vercel deployment step for future preview deployments (requires maintainer to configure secrets: VERCEL_TOKEN, ORG_ID, PROJECT_ID).

2. Test Workflow (.github/workflows/deploy-preview.test.yml)

   • Validates that deploy-preview.yml exists and is configured correctly.
   • Ensures the workflow triggers on PRs to main.
   • Confirms repository checkout works and Node.js 20 is installed.
   • Verifies root and client dependencies install correctly.
   • Builds the client application and checks for build output.
   • Validates Vercel deployment step configuration and required secrets.
   • Ensures deployment step comes after the build step.

Motivation

• Currently, contributors don’t have CI/CD previews for pull requests, which requires maintainers to pull and build branches locally.
• This workflow enables maintainers to automatically build and optionally deploy PRs in the future.
• The test workflow ensures configuration correctness before any merge.

Testing

• Workflows were tested in my fork:
  • deploy-preview.yml triggers correctly on PRs to main.
  • Dependencies install without errors.
  • Client build completes successfully.
  • Test workflow validates all steps and secrets configuration.

Notes for Maintainers

• To enable Vercel previews, the main repository will need the following secrets configured:
  • VERCEL_TOKEN
  • ORG_ID
  • PROJECT_ID
• GITHUB_TOKEN is automatically provided by GitHub Actions.