fix(ci): install pnpm in the release workflow

[llbbl]

Urgent — releases are currently blocked until this lands.

What happened

PR #28 unskipped the CLI integration tests, which shell out to whichever package manager the fixture declares. tests/fixtures/sample-project ships a pnpm-lock.yaml, and ubuntu-latest does not provide pnpm. A pnpm/action-setup step was added to ci.yml, but auto-release.yml also runs the full suite in its Verify step and was missed. The release run after #28 merged failed with 12 JSON.parse ... Unexpected EOF errors — empty stdout because the CLI could not find pnpm.

Why no damage was done

This is the failure mode the restructure in #18 was built for. Verify failed, Commit and push version bump was skipped, and the build and release jobs never ran. No version bump reached main and no tag was pushed — the latest tag is still v0.5.1 and main is untouched. Under the old ordering the tag would already have been pushed before the build ran, leaving an orphan tag and a 404 for the Homebrew tap.

The fix

Mirror the pnpm setup step from ci.yml into the version job of auto-release.yml, pinned to pnpm 11.9.0. Only that job runs tests — the build and release jobs do not — so one step is sufficient.

Verification

actionlint clean on both workflows; confirmed by grep that version is the only job invoking just test.

Test plan

• actionlint passes on auto-release.yml
• Next release run's Verify step succeeds with pnpm available