User retention

[kruscho]

Hi,

for managing user and to meet the legal requirements in some countries, i would nice to have an overview about the user in the ui. Sortables columns like "created" and "last seen / last login" could help to delete users, who are not using the platform anymore.
One step further would be to define some retention times for the user like "disable user after this user is not logged in during the last month" and "delete user after 6 month of inactivity"