Fourth Phase D smoke article. Previous three failed:

1. Wrong allowlist patterns (denials) — fixed in b63725e.
2. Env-loading bug in start_orchestrator.sh — fixed in 51de704.
3. PAT lacked Contents:write on the selected repo — fixed by Chad regenerating the PAT.

This one should succeed: clone, write src/content/blog/smoke-phase-d.md, commit, push, CF Pages rebuild.