seatd is a seat management daemon, that does everything it needs to
do. Nothing more, nothing less. Depends only on libc.

libseat is a seat management library allowing applications to use
whatever seat management is available.

Supports:
- seatd
- (e)logind
- embedded seatd for standalone operation

Each backend can be compile-time included and is runtime auto-detected
or manually selected with the `LIBSEAT_BACKEND` environment variable.

Which backend is in use is transparent to the application, providing a
simple common interface.