lock

type FileLock interface {
	// Acquire attempts to acquire the lock, polling every 100ms until
	// the lock is acquired, the timeout elapses, or the context is cancelled.
	// Returns an error naming the path and the elapsed timeout on failure.
	Acquire(ctx context.Context, timeout time.Duration) error
	// Release unlocks and removes the lock file. Idempotent — calling on an
	// already-released lock returns nil.
	Release(ctx context.Context) error
}

type Locker interface {
	Acquire(ctx context.Context) error
	Release(ctx context.Context) error
}