NeoForge's mod scanner rejected brassandsigil_tweaks-1.0.0.jar because
PowerShell 5.1's [ZipFile]::CreateFromDirectory() writes Windows-native
path separators into ZIP entry names on Windows. Entries came out as
"META-INF\neoforge.mods.toml" instead of the spec-required forward-slash
form, so the loader couldn't find the manifest and silently dropped the
jar with "not a valid mod file".
Build-Tweaks.ps1 now opens the archive in 'Create' mode and writes each
file as an explicit ZipArchiveEntry whose name is built from the relative
path with backslashes replaced by forward slashes. Verified the rebuilt
jar lists "META-INF/neoforge.mods.toml" etc.
Pack version 0.9.2 -> 0.9.3 so launchers cached at 0.9.2 see "pack
changed" and re-sync the new tweak jar (their bytes differ; SHA-1 in the
manifest will reflect that).