Fixes a severe UPS problem: check_platform_warehouse() searched an entire surface for the space platform hub every 80 ticks. A Space Freezing Warehouse placed on a planet made the mod scan that whole planet 45 times a minute for an entity that cannot exist there, costing 150-175 ms per scan. The hub is now read directly from LuaSurface.platform.hub. Behaviour is unchanged; verified to return the identical hub on platforms. Everything else is the original mod. Disable the original Fridge before enabling this.