Turborepo CI on GitHub Actions

Turborepo reports a cache miss on every CI run.

Why it happens

The local .turbo cache is discarded and no remote cache is configured, so every task re-executes.

What to change

1. Configure Turborepo remote caching so CI and developers share artefacts
2. Cache .turbo locally as well for within-run reuse
3. Make sure task inputs are declared correctly — over-broad inputs cause false misses
4. Use --filter to build only the packages affected by the change

Turborepo on runnerhut

jobs:
  build:
    runs-on: runnerhut-8vcpu-ubuntu-2404
    env:
      TURBO_TOKEN: ${{ secrets.TURBO_TOKEN }}
      TURBO_TEAM: acme
    steps:
      - uses: actions/checkout@v4
      - run: npm ci
      - run: npx turbo build test --filter=...[origin/main]

The only runnerhut-specific line is `runs-on: runnerhut-8vcpu-ubuntu-2404`. Everything else is standard GitHub Actions — the same actions, the same secrets and the same permissions model you use today.