Fix crash under Proton due to case-sensitivity

[Kaydax]

For some God forsaken reason, forcing the path to be lowercase here under Proton causes a System.IO.DirectoryNotFoundException due to case-sensitivity. Removing ToLowerInvariant() in the creation of the LocalFileSystem fixes the issue and allows the game to boot under Proton again.

[Copilot]

Pull request overview

This PR fixes a crash when running the game under Proton (Linux compatibility layer for Windows games) by removing case normalization from filesystem path initialization. The issue occurred because Linux filesystems are case-sensitive, and converting the root folder path to lowercase caused a System.IO.DirectoryNotFoundException when the actual path contained uppercase letters.

• Removes ToLowerInvariant() call when converting the root folder path in LocalFileSystem constructor
• Allows the filesystem to respect the actual case of directory paths on case-sensitive filesystems

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[garrynewman]

This should really be fixed in Proton, not here.

[Kaydax]

This should really be fixed in Proton, not here.

This is a regression with s&box itself, not Proton. There isn't an easy way to properly fix it in Proton due to how Linux is heavily case-sensitive. A better solution is to not assume case insensitivity in the code base, which I have another branch for that

[Zipdox2]

This should really be fixed in Proton, not here.

It should not. Changing case sensitivity in the entirety of Proton is very extreme. I would like to ask what problem using ToLowerInvariant fixes in the first place.

[handsomematt]

Here's when I changed it 6.5 months ago, not a few days ago when the regression started - it was done because every other bit of filesystem code normalizes to lowercase, so you would be removing it in one place only and fucking up everything it fixed before that.

I don't want to accept any fix that doesn't understand the problem fully, and doesn't understand the issues they'd cause throughout the rest of the engine.

[Kaydax]

I apologize, the mistake was on my end. The entire issue was caused by a bug with steam that caused library paths with Uppercase paths to become all lower case, thus causing the problem. The fix is to remove the library and re-add it, fixing the issue.