Module cache 

Lock file management and cache decision logic (PB-004)

Handles lock file persistence (atomic write via temp+rename) and cache hit/miss determination with detailed invalidation reasons.

Enums

CacheDecision

Cache decision for a stage

Functions

check_cache

Check cache status for a stage

load_lock_file

Load a lock file if it exists

lock_file_path

Derive the lock file path from a playbook path: .yaml → .lock.yaml

save_lock_file

Save a lock file atomically (write to temp, then rename)