ci: add format check job to CI workflow

[Rodriguespn]

What

Adds a new format job to the CI workflow that runs pnpm run format:check to verify code formatting using Biome.

Changes

• Renamed .github/workflows/tests.yml to .github/workflows/ci.yml
• Added format job that checks code formatting with Biome
• Format job runs only on pull requests (not on push to main)
• Format job runs in parallel with the existing test job

Why

This ensures all PRs are properly formatted before merging. The format check only runs on pull requests so we can always run the full test suite against main after merging without the format check overhead.

[mattrossman]

I think it's preferred to run biome ci like we do in infrastructure. Currently this runs biome check.

Biome offers two CLI commands to run all checks: biome check and biome ci, however the latter should be used in CI (Continuous Integration) environments.

https://biomejs.dev/recipes/continuous-integration/

[mattrossman]

Also, consider using the official GitHub Action for setting up biome (see infrastructure biome.yml for reference)

https://biomejs.dev/recipes/continuous-integration/#github-actions

[Rodriguespn]

Thx for the heads up @mattrossman. I'm not used to work with Biome so I wasn't aware of the difference between biome check and biome ci. I've checked infra biome.yml but decided to go with something closer to Biome ci official docs

name: Code quality

on:
  pull_request:

jobs:
  quality:
    runs-on: ubuntu-latest
    permissions:
      contents: read
    steps:
      - name: Checkout
        uses: actions/checkout@v5
        with:
          persist-credentials: false
      - name: Setup Biome
        uses: biomejs/setup-biome@v2
      - name: Run Biome
        run: biome ci .

[mattrossman]

Thanks!