Fix) Have builtin cd to handle spaces in folder name

[exxocism]

Project issue/Description

• Vibe coded to have builtin cd to handle spaces in folder name

  Fix shell word-splitting issues when working with directories containing spaces (e.g., Program Files)
  Quote all variable expansions in find_local_pkgset that may contain paths with spaces
  Fix cd function override to preserve argument boundaries using "$@" instead of unquoted $*
  

Major changes

• Have builtin cd to handle extra spaces: 78ca74b
• Have find_local_pkgset to handle extra spaces: 246b5a9

Minor changes

• None

Test env

• Open a new terminal or re-source your shell config
• Navigate to a directory with spaces in the name: cd "Program Files"
• Verify no "too many arguments" or syntax errors occur
• Verify GVM's auto-switching of Go versions still works when changing directories