0x08 (BS) was treated as plain backspace alongside 0x7f (DEL). On Windows Terminal, Backspace sends 0x7f and Ctrl+Backspace sends 0x08, making ctrl+backspace bindings unreachable. Now 0x08 matches ctrl+backspace (and ctrl+h, same byte) but not plain backspace. 0x7f remains plain backspace. fixes #2139