* feat(#1494): add workflow.mvp_mode to VALID_CONFIG_KEYS; document code_review_command, plan_chunked, mvp_mode in planning-config.md Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com> * chore: backfill PR number 1500 in changeset Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com> --------- Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>