Document and verify the compatible Codex runner invocation

Changes: Document the coordinator-selected Codex 0.159.0 argv without conflicting sandbox flags; record parser and filesystem evidence plus QA handoff. Preserve existing local configuration and portable example.
Validation: Exact active argv help and approved host wrapper with inner workspace-write probe exited 0; project write/read/remove passed and outside write denied EROFS30. Final make check passed 72 tests after shortening the documentation to meet prompt budgets. No additional model or storage work ran.
