Multi-phase plan

A checklist an owner runs box by box and an auditor can check from the evidence. Finish the plan before executing its units.

Repo layer first. Read the repo's AGENTS.md/CLAUDE.md and, if it exists, the overlay .agents/bento/bento-multi-phase-plan.md at the repo root; follow it under the overlay rules.

Delivery follows the request

• Plan only (including a direct invocation without an implementation request): deliver the plan and stop; don't change application code.
• Preparation inside an implementation request: finish the plan, then continue the authorized work without another go-ahead. Pause dependent work for unresolved product decisions; a planning step does not revoke authorization or grant permission to push/PR.

Steps (paste as todos)