Option A: ROADMAP.md only — Agent reads/writes natural language. No impedance mismatch.

Option B: Vision Tracker only — Queryable, filterable, interactive, visual dependency graphs.

Option C: Both, kept in sync — Manual sync will fail. Two sources of truth means zero.

Option D: Tracker primary, markdown generated — Single source of truth. Git-diffable snapshots on demand.

The key insight: if the tracker is the agent's work queue, the agent has self-interest in keeping it current.