Vue CI on GitHub Actions

Vite rebuilds the dependency pre-bundle on every CI run.

Why it happens

node_modules/.vite holds the optimised dependency bundle and is thrown away.

What to change

1. Cache node_modules/.vite keyed on the lockfile
2. Run vitest with --pool=threads to use every core
3. Build and test in the same job so the pre-bundle is reused

Vue on runnerhut

jobs:
  test:
    runs-on: runnerhut-4vcpu-ubuntu-2404
    steps:
      - uses: actions/checkout@v4
      - run: npm ci
      - run: npx vitest run --pool=threads
      - run: npm run build

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.