Map Fix Stalker Coop by DUB

Stalker Coop by DUB
Clean rebuild of the Alfazone world for Stalker Coop PVE.
The old map layer stack was messy and hard to update. This version takes the working Stalker PVE content (spawns, loot, mutants, events, traders) and drops it onto a cleaned Alfazone world so the scenario loads stable and stays editable.