migration 0031: app_user_roles table — composite PK (app_id, user_id,
role) so add is idempotent (ON CONFLICT DO NOTHING). v1.1.8 stores
strings only; permission matrices / hierarchies / role registry are
explicitly v1.2 work per the brief.
UsersServiceImpl wires roles: Arc<dyn AppUserRoleRepo>:
* fetch_roles() now actually queries the repo (replacing the empty
Vec stub from commit 4). Every AppUser returned from get /
find_by_email / list / update / verify / login now carries its
role list.
* users::add_role gated on AppUsersAdmin; first checks the user
exists in this app so a FK violation can't leak "no such user".
* users::remove_role gated on AppUsersAdmin; idempotent.
* users::has_role gated on AppUsersRead.
* accept_invite now applies pre-staged roles atomically with the
user creation; malformed role strings are skipped with a warn
rather than aborting the whole accept (the invitation was an
admin's promise — we honor as much of it as we can).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>