OpenReception: Staff deletion removes pending invites cross-tenant by email match

OpenReception's appointment booking software provides an end-to-end encrypted appointment booking platform. Prior to version 1.0.6, when a TENANT_ADMIN deletes an existing staff user, the underlying `StaffService.deleteStaffMember()` runs an additional invite cleanup that deletes from the central `user_invite` table by email. The `email` clause has no `tenantId` predicate. Any pending invite in any tenant that shares the deleted staff's email is removed. A TENANT_ADMIN of tenant A who deletes a staff record with email `victim[@]example[.]com` also deletes the pending invite for `victim[@]example[.]com` in tenant B, even though they have no relationship to tenant B. The user-side delete is correctly scoped (`eq(user.id, staffId), eq(user.tenantId, tenantId)`), and the pending-invite-only delete path (when `staffId` is itself an invite ID) is also tenant-scoped. The bug is specifically in the invite cleanup that runs as a side effect of deleting an existing staff user. Version 1.0.6 patches the issue.