Forward publication base ref (#156)

[chubes4]

Summary

Forward the reusable workflow base_ref into runner-workspace publication as base, while preserving materialization as from: "origin/" + base_ref.

Evidence

• Issue: Forward base_ref to WP Codebox publication config #156
• Source relationship: the reusable maintain-docs.yml workflow already passed INPUT_BASE_REF to its jq runner-workspace builder and used it for from; publication was the missing consumer.
• Change kind: minimal workflow-contract correction plus deterministic contract coverage.
• Verification capability: the contract evaluates the emitted jq expression with baseRef=trunk, requiring base=trunk and from=origin/trunk.
• Scope: this only supplies the existing explicit base to runner-workspace publication. It does not alter WP Codebox fallback behavior or any other workspace fields.

Tests

1. Run php tests/validate-docs-agent-packages.php (passed).
2. Run php -l tests/validate-wp-codebox-run-agent-task-contract.php (passed).
3. Run jq -cn --arg repo 'Automattic/example' --arg branch 'docs-agent/docs-upkeep' --arg baseRef trunk '{enabled:true,repo:$repo,clone_url:("https://github.com/" + $repo + ".git"),branch:$branch,branch_prefix:$branch,base:$baseRef,from:("origin/" + $baseRef)}' | jq -e '.base == "trunk" and .from == "origin/trunk"' (passed).
4. Run WP_CODEBOX_DIR=/path/to/wp-codebox php tests/validate-wp-codebox-run-agent-task-contract.php with the declared v0.12.27 checkout. This is currently blocked before Docs Agent assertions because that release lacks contracts/run-agent-task-reusable-workflow-interface.v1.json; the validation gate was not bypassed or changed.

Compatibility

Consumers that omit base_ref retain the default main. Consumers that explicitly set a non-main base such as trunk now use it consistently for both runner-workspace publication and origin/trunk materialization.

AI Assistance

Assisted by openai/gpt-5.6-terra.