Same contract as issue-close (7a38eed1): -b/--body canonical comment
flag with -c/--comment alias; usage errors stderr + exit 2 (unknown
option, missing required, value-less flags); GitHub-path provider
failures normalized to exit 1.
Both new suites enrolled in framework-shell CI (enumeration guard OK,
population 76). pr-close's suite uses FAILING provider stubs (exit 99):
its API fallback treats a successful curl as a closed PR, so exit-0
stubs let sandbox arms succeed (measured); post-sandbox contact
assertions are correspondingly scoped, parser arms remain zero-contact.
Mirrored to the brain tree; all usage-contract suites green in both.
marcie
7e4de270dc