This change removes the forced assignment of vim.o.winborder in the confirmation window setup, leaving win_opts.border nil so Neovim will automatically apply either the user’s custom border or its default. It restores support for custom border characters that was broken by a previous PR and keeps the project’s UI consistent with user settings. However, documentation wasn’t updated to reflect this change, formatting checks were skipped, and there may still be edge cases on older Neovim versions or empty-border scenarios.