🚨 test(terminal-columns.test.ts): add tests for terminalColumns function

✨ feat(terminal-columns.test.ts): add tests for various edge cases, padding, alignment, processing, static widths, percent widths, content-width, auto, and breakpoints.
This commit adds tests for various edge cases, padding, alignment, processing, static widths, percent widths, content-width, auto, and breakpoints. The tests ensure that the terminalColumns function works as expected and that it handles different scenarios correctly.