[Copilot]

Evolves setup-raku from a compiler installer into a fuller Raku development environment: hardened release resolution, zef module installation and caching, and actionable outputs for downstream jobs.

Installer hardening

• Validates raku-version input (latest or YYYY.MM[.N]) with a clear error.
• "Not found" errors now list platform, arch, and available versions.
• Fixes cache dir naming when build_rev is null (previously produced -0null) via new cacheVersion().
• Short-circuits on tool-cache hits — re-runs skip the download entirely.
• Grouped log output around download/extract.

New inputs & outputs (action.yml)

• zef-modules: space/comma-separated modules installed via zef install after setup; zef --version is verified first with a clear failure message.
• enable-zef-cache: caches ~/.zef via @actions/cache, keyed on a SHA-256 of META6.json.
• Outputs raku-version (resolved) and raku-path for downstream steps.

- uses: Raku/setup-raku@v1
  id: raku
  with:
    raku-version: "latest"
    zef-modules: "Test::META Cro::Core"
    enable-zef-cache: "true"
- run: raku -I. -MTest::META -e 'meta-ok'   # uses ${{ steps.raku.outputs.raku-path }}

Testing

• New offline unit tests mocking @actions/http-client: latest selection, build_rev ordering (incl. null), platform/arch/backend/type filtering, no-match → null, cacheVersion, parseZefModules, zefCacheKey.
• Existing live tests moved to tests/installer.integration.test.ts; full suite runs by default.

CI

• Dogfood matrix adds macos-latest and latest, plus a smoke step (raku -e 'say "ok"', zef --version).
• test.yml gains a dist-consistency check (git diff --exit-code dist/).

Docs

• README documents inputs/outputs with zef and caching examples; CHANGELOG gets an Unreleased entry.

Note: CodeQL flags 4 alerts in dist/index.js, all inside bundled dependency code (undici WebSocket SHA-1 handshake, fast-xml-parser regex via @azure/core-xml) — no first-party source findings.