Summary

• Removes the impossible runtime comparison against the caller-associated github.workflow_ref.
• Retains exact-semver helper input validation, fixed Automattic/wp-codebox checkout, resolved-tag commit verification, and package version verification.
• Adds a static regression fixture for the foreign caller ref from Build run 29295530010 while retaining paired-tag consumer contracts.

Evidence

• Fixes Remove impossible reusable workflow self-ref check #1761
• Regression source: https://github.com/Automattic/build-with-wordpress/actions/runs/29295530010

Tests

1. npm run build
2. npm run test:agent-task-contracts
3. npm run test:agent-task-workflow-interface
4. npm run test:production-boundary-enforcement
5. npm run test:runtime-tool-policy
6. /opt/homebrew/bin/actionlint .github/workflows/run-agent-task.yml
7. git diff --check

AI assistance

• AI assistance: Yes
• Tool(s): OpenAI gpt-5.6-terra and OpenCode
• Used for: Investigated the workflow context behavior, implemented the workflow, documentation, and regression-contract changes, and ran local verification.