Zig Rewrite - Zig 0.12.0 and more!

[Kawaii-Ash]

Changes

• updated to use Zig v0.12.0
• allocator is no longer needed in authenticate
• replaced some functions in interop to use the Zig equivalent
• mapped blank_password to clear_password for compatibility with old config
• cursor is set to the end of the user input when next focused after loading from a save file
• save.ini is expected to be in the same dir as the config
• changed save migrator to load from old save format correctly. (loads file from config.save_file)
• some general code improvements

Fixes #598