support for deleting exactly one word using alt(option) + backspace

hello,
we could enable moving one word back and forth by settings in config-> keyboard -> option -> `AS MODIFIER` to `Esc`.

it would be nice if we could get deleting one word using alt(option)+backspace in blink shell.

i.e. use case:

let’s say you typed `ssh vm10.home`, but you want to ssh to `vm10.work` instead.
you could delete `home` by pressing option+backspace which leaves you with `ssh vm10.` and type you can type `work` to ssh to vm10.work.

thank you.

The issue names no files, tests, or entry points. Start by locating Blink's keyboard handling and the existing option-key word-navigation behavior, then verify the requested deletion leaves the preceding command text intact and test it on the stated SSH example.

Written by the indexing model from the issue text.