Move the allowed_bots check in checkHumanActor and checkWritePermissions so
it only fires after the actor has been resolved as a non-User account
(GitHub App / bot, or unresolvable app actor). Actors that resolve to a
regular User account go through the standard human/write checks regardless
of allowed_bots.
The Copilot-style path (GITHUB_ACTOR not ending in [bot] and not resolvable
as a user) is unchanged: it still falls through to the existing 404 catch,
which already consults allowed_bots once the API has reported the actor is
not a user.
Update tests to match and add coverage for the User-account path.