Forbid deleting the last staff user

[felixrindt]

depends on #1037 so rebase main onto that first

• protect actions that lead to no active user having management permissions (removing users from groups etc)
• add more tests

[coveralls]

Changes unknown when pulling 138998c on fix-cannot-delete-last-staff-user into ** on main**.

[jeriox]

do we want to implement similar checks for at least one group with the "can manage ephios instance" permission? AFAIS you could loose that permission and even staff users wouldn't be able to recover it

[felixrindt]

do we want to implement similar checks for at least one group with the "can manage ephios instance" permission? AFAIS you could loose that permission and even staff users wouldn't be able to recover it

I think that's a very good idea. UX wise we could also just disable the delete button instead of showing the error only after people hit delete. What do you think?

[jeriox]

do we want to implement similar checks for at least one group with the "can manage ephios instance" permission? AFAIS you could loose that permission and even staff users wouldn't be able to recover it

I think that's a very good idea. UX wise we could also just disable the delete button instead of showing the error only after people hit delete. What do you think?

yes that would be a bit smoother, but I could also live with the version you implemented here