The command/binary name was accepted verbatim and interpolated into
debian/install, debian/rules, debian/tests/smoke, automake variables,
meson.build and [project.scripts]: a value with a space or quote broke
the install lines and shell snippets, 'my.tool' parsed as a nested TOML
table (silently dropping the console script) and produced non-canonical
automake variable names. Both --command and the wizard answer now go
through a shared validator (lowercase identifier: letters, digits,
+ - . _).