Graphical console greeter for greetd

 A terminal greeter for the greetd login manager daemon using Rust tui to
 render login prompt widgets to the terminal. It supports:
 .
  - displaying the current date and time
  - fetching sessions from /usr/share/xsessions and /usr/share/wayland-sessions
  - remembering the last user and their chosen session
  - shutdown and reboot
  - displaying all usernames returned by NSS in a drop-down menu