Expose viewer.invitingOrganizations: [Organization!]! returning the
organizations that have a live pending invitation directed at the
current identity (accepted_at IS NULL AND expires_at > NOW()). The
list is rendered under a "Pending invitations" section on the
memberships page and in the organization selector dropdown, so a user
already signed in with an existing identity can see which
organizations have invited them without having to dig through their
inbox.
The new field is gated by iam:invitation:list against the viewer's
own identity, so it does not loosen authorization on Organization
elsewhere. E2E coverage validates the live-pending case, the
no-invitation and post-accept cases, and a multi-org scenario.
Signed-off-by: Sacha Al Himdani <sacha@getprobo.com>