appointmentEventConflicts
Returns active scheduling conflicts (overlap and blocked) for the given
users within a time window. Reads from the Postgres source-of-truth so
callers always see post-mutation freshness. Time-off conflicts are
normalized to blocked.
Arguments
DateTime!Exclusive end of the conflict window
DateTime!Inclusive start of the conflict window
[ID!]!The users whose appointments should be checked
Returns
[AppointmentEventConflict!]!