TheLazyTomcat/SII_Decrypt ? reverse-engineered prompt

Build me a small Pascal based tool for working with SII save files from Euro Truck Simulator 2 and American Truck Simulator. I want it to decrypt normal encrypted SII files, and if the file is in the game’s binary save format it should automatically decode it into readable text without me needing to change any in game setting first. It should also support decoding 3nK encoded SII files that are usually used for localization.

Please make it usable in a few ways, as a simple desktop app with file pickers and a run button, as a console app where I can pass an input file and optionally an output file, and as a reusable library I can call from other Pascal code or load as a DLL. If no output file is given in the console tool, just overwrite the source file. Keep it practical and Windows friendly, and include whatever test files or small tester app make sense. Look up current docs online if you need to.