MoganSTEM v2026.1.2 constructs Ghostscript command lines incorrectly on macOS when temp paths contain spaces

[Matthias-A-Steiner]

On macOS, MoganSTEM splits Ghostscript argv at spaces even when attempting to escape paths, breaking PS/EPS rendering when the user’s full name contains spaces. Reproducible with official dmg 2026.1.1. and dmg 2026.1.2.

[dorodb-web22]

Submitted a fix in #2859 , the issue is that
sys_concretize
backslash-escapes spaces, which GS doesn't handle in option values.

Switched to
raw_quote
to double-quote the paths instead.