## Goal
- This PR only updates design, plan, checklist, or TODO material.

## Outputs
- New or updated design docs:
- New or updated TODO / plan entries:
- Planned phases or milestones:

## Key Decisions
- Decision 1:
- Decision 2:
- Explicitly deferred:

## Validation
- [x] Plan or design reviewed for scope clarity
- [x] Proposed phases and ownership are clear
- [ ] No code execution was required

## Follow-up
- Expected implementation PRs or branches:
