Scrub the last "-" mention from the --validate usage doc (the escape no
longer exists, so the header asserted the opposite of the behavior), and
add the negative bats case the tightened branch was missing: a suite
whose hardcoded mapping names a PackageSource absent from the graph must
fail validation with the "maps to ..., not a PackageSource" error.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Signed-off-by: Andrey Kolkov <androndo@gmail.com>