Manage Locks Skill

The single home for cross-session coordination primitives in plan-marshall. Both primitives serialize concurrent sessions against the MAIN checkout regardless of which worktree the caller is pinned to, and both sit on one shared, TOCTOU-safe, main-anchored read-modify-write + plan-liveness core (scripts/_locks_core.py). The skill is script-deterministic — pure file coordination, no LLM judgement.

Two primitives live here: