Texture pack filenames/aliases from textures.ini were used to build read
and write paths with no '..' check, letting a malicious pack read or
write files outside the pack directory.
- LoadIniValues rejects entries with a parent dir component via
HasParentDirComponent.
- ReplacedTexture::Prepare skips such filenames as defense in depth.
- PSPLoaders savestate migration now uses the shared HasPathTraversal
helper instead of inline separator checks.