Document workflow run awaiting

[chubes4]

Summary

• document the workflow run awaiter contract generated by the accepted hosted Docs Agent run
• mark the bounded PR feat: add workflow run await service #422 documentation drift as satisfied so future maintenance may no-op
• move future publication off the stale post-squash branch tracked in WP Codebox #1894

Replaces the polluted generated branch in #444.

How to test

1. Run composer install --no-interaction --prefer-dist --no-progress.
2. Run composer test.
3. Run php tests/no-product-imports-smoke.php.
4. Check out Docs Agent 7b67d341eea16b75b8e055507d36a8d8e69a1fe3 and WP Codebox a6fe2d208e990a8d04104aa74aacbb8d1539fbc1.
5. Run DOCS_AGENT_DIR=/path/to/docs-agent WP_CODEBOX_DIR=/path/to/wp-codebox php tests/docs-agent-native-workflow-contract.php.
6. Run actionlint .github/workflows/*.yml and git diff --check.

Hosted generation proof: https://github.com/Automattic/agents-api/actions/runs/29745532621

Compatibility

Documentation and workflow policy only. Runtime APIs are unchanged. The publication branch changes because the prior branch retained post-squash history; see Automattic/wp-codebox#1894.

AI assistance

• AI assistance: Yes
• Tool(s): Native Docs Agent with OpenAI GPT-5.5; OpenCode with GPT-5.6-sol
• Used for: The hosted Docs Agent drafted the source-grounded awaiter documentation; OpenCode isolated it onto current main, updated deterministic lifecycle policy, and verified the result with Chris reviewing and owning the change.