Admin → Agent → Spending: what every user spent on the assistant today and
this month, and how many turns they started today — everyone who used it
this month, also a user who no longer holds agent. Money comes from the AI
request journal (PhoenixKitAgent.Spend, micro-dollars shown as dollars;
only endpoints that report a cost add to it), in the day and month of the
site time zone.
Needs agent.manage: the tab is registered under that key and the page
checks it again on mount (PhoenixKitAgent.Web.Access). It has no events.