seatd is not currently tracking which devices are part of which seat.

An ability to assign devices to seats is necessary. Ideas:

• A static or runtime-reloadable configuration file, containing device-to-seat mappings.
• An IPC mechanism and command-line tool to dynamically assign devices to a seat.

In case of dynamic solutions, it may be necessary to add device_added/device_removed events to avoid races with seat clients otherwise doing their own device tracking.

Direct udev/devd integration should preferably be avoided.