The "clapper_src" directory name was unusual. This was done to make it work as a widget for other apps. Now that this functionality got removed it can be named simply "src" as recommended by guidelines.
Daemon is responsible for starting and later watching over spawned "broadwayd" and "remote" app needed for remote playback control. We cannot use systemd n Flatpak, so we make do with running optional background subprocesses.
I know that this should be done using some sort of build system (like meson), but the player is still far from finished and a basic install script should be sufficient for the time being, if anyone wishes to test it.