theaperturecat/csgo-branch-fixed ? reverse-engineered prompt

Build me this Source engine mod project so I can run Portal 2 and Half Life 2 on the improved CSGO branch.

I want the setup to be as smooth as possible, with clear steps for getting the right old CSGO depot, copying over the needed game files, building the project in Release mode, and launching it with the provided run script. If anything is missing or tricky, please make the setup more forgiving and add helpful notes so a normal person can follow it.

The main goal is to get this branch working well enough for Portal 2 and HL2, including the episodes that are already supported, and make it easier to build future mods on top of it. If you need to check current Source engine docs or other references online, do that.

Please keep the project working with the existing code and structure, and make sure the build succeeds cleanly.