Send a device event
Ingests a message from a registered IoT device. AURA applies the device's
template (selected by `device_type_id`) to interpret the message and map it
to an AURA action — raise a callout, update location, cancel a callout, or
record a battery/health update. The accepted fields depend on the device
template; see the Device & payment gateway guide for the mapping and more
examples.
