new upgrade: regenerative passive overshield

[0XDE57]

Passive Regen Shield [1,2,3,4] - rechargeable overshield -> some forgiveness

Levels: [1,2,3,4]
Protection: 25, 50, 75, 100
Cooldown: 20s,??,10s?

Take the edge off the initial hit with a rechargable overhshield! Passive means you don't even have to do anything!
It will take damage before the hull. Any extra damage beyond the shield value is passed onto the hull.
When overshield is fully depleted, it will break/overheat and require a long cooldown before reactivating.

Like the active shield, this will protect the ship.