Project-scoped external assignees without Kaneo accounts
What would you like to change?
I would like to assign a task to someone outside Kaneo without creating an account or inviting them to the workspace. Projects sometimes need to track work owned by a company or contractor that never signs in.
Project members could create named external assignees and select them in the same field as workspace members. These entries would be limited to one project, clearly marked as external, and have no login or workspace permissions. They would receive no Kaneo notifications and would not appear in @mention suggestions.
Additional context
The task assignee currently points to a user account, and the API checks that the user is a current workspace member. An external assignee would be a tracking entry with no authentication. A task could be assigned to "Acme Consulting", for example, even though nobody at Acme has access to Kaneo. An optional free-text note could name the contact person.
Task history should keep the displayed name if the external entry is later renamed or removed. Each entry should only be available in the project where it was created.
Originally requested by @thriz0 on 2026-09-28. Original GitHub request #1843.