feat: invitation accept screen and api

test/invitations_test.go

@@ -75,6 +75,19 @@ func (m *inviteFakeRepo) Delete(id uint32) error {
 	return nil
 }
 
+func (m *inviteFakeRepo) MarkAccepted(id uint32, at time.Time) error {
+	if err := m.fail.trigger("MarkAccepted"); err != nil {
+		return err
+	}
+	stored, ok := m.invites[id]
+	if !ok {
+		return invite.ErrInviteNotFound
+	}
+	stored.AcceptedAt = &at
+	m.invites[id] = stored
+	return nil
+}
+
 var _ invite.Repository = &inviteFakeRepo{}
 
 func inviteAt(email string, createdAt time.Time, expiresAt time.Time) invite.Invite {