Locked
◀ door opens key knob spring latch LINEAR SERVO slot (lost-motion) slider lever (pull ← to open) ◀— pull
slider lever servo + link pin (free in slot) spring latch
1 · LockedSpring latch holds the door.
2 · RetractServo pulls the lever left.
3 · Held openLatch held — you open the door.
4 · ReleaseDoor open, servo lets go.
5 · Auto-lockDoor shuts, latch re-locks.