Implement user links

backend/app/models/user.py

@@ -1,6 +1,6 @@
 from typing import TYPE_CHECKING
 
-from pydantic import EmailStr
+from pydantic import EmailStr, field_validator
 from sqlmodel import Field, Relationship, Session, select
 
 from app.core.security import get_password_hash, verify_password
@@ -46,10 +46,6 @@ class PermissionRight(DocumentedIntFlag):
     ADMIN = CREATE | READ | UPDATE | DELETE | MANAGE_USERS | MANAGE_TEAMS
 
 
-class PermissionRightObject(BaseSQLModel):
-    rights: PermissionRight | None = Field(default=PermissionRight.READ, nullable=False)
-
-
 # ##############################################################################
 # link to User (many-to-many)
 class UserRoleLink(BaseSQLModel, table=True):