Cypress CI on GitHub Actions

The Cypress binary downloads every run and specs execute serially.

Why it happens

~/.cache/Cypress is not persisted and parallelisation requires explicit configuration.

What to change

1. Cache ~/.cache/Cypress keyed on the Cypress version
2. Split specs across a matrix and run them in parallel
3. Disable video recording in CI unless you actually watch the videos
4. Use cypress run --component and --e2e as separate jobs

Cypress on runnerhut

jobs:
  e2e:
    strategy:
      matrix:
        containers: [1, 2, 3, 4]
    runs-on: runnerhut-4vcpu-ubuntu-2404
    steps:
      - uses: actions/checkout@v4
      - uses: cypress-io/github-action@v6
        with: { record: true, parallel: true }

The only runnerhut-specific line is `runs-on: runnerhut-4vcpu-ubuntu-2404`. Everything else is standard GitHub Actions — the same actions, the same secrets and the same permissions model you use today.