Bug Fixes
- safe deletion with FK reference cleanup before removing employee
- remove unused InvitationsResponse export
Features
- add employee invitation email template with accept/reject CTAs
- detect existing users and send invitation instead of blocking
- handle invitation_sent response in add employee dialog
- add CRUD API routes with public accept/reject endpoint
- add public accept/reject page for employee invitations
- add EmployeeInvitation model with InvitationStatus enum
- add invitation management section to employees tab