Add W011: detect when STATE.md says current phase is N but ROADMAP.md shows it as [x] complete (can happen after crash mid-phase-complete). Add W012-W015: validate branching_strategy against known values, context_window as positive integer, phase_branch_template has {phase} placeholder, milestone_branch_template has {milestone} placeholder.
Add stateReplaceFieldWithFallback diagnostic: warn when neither primary nor fallback field name matches in STATE.md (surfaces template drift from external edits).
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
