Terminal borders that don't cost a cell

A developer working on Ratatui has created a new terminal protocol that draws borders on cell edges rather than consuming entire rows or columns, enabling cleaner UI design in terminal applications. The approach has been implemented as a patch to the Ghostty terminal and includes fallback support for traditional Unicode box-drawing characters when the feature isn't available. This allows terminal UIs to display more content while maintaining better visual separation between elements like panes, text fields, and buttons.