treewide: include PipeWire op and enforce PulseAudio check

This fully replaces PulseAudio with PipeWire and enforces the PulseAudio check and error message. The pipewire-pulse daemon is handled in the NixOS module.

Closes #26.

Signed-off-by: Ophestra <cat@gensokyo.uk>

nixos.nix

@@ -196,6 +196,15 @@ in
                             }
                           ]
                         )
+                        ++ optional (app.enablements.pipewire && app.pulse) {
+                          type = "daemon";
+                          dst = if app.mapRealUid then "/run/user/${toString config.users.users.${username}.uid}/pulse/native" else "/run/user/65534/pulse/native";
+                          path = cfg.shell;
+                          args = [
+                            "-lc"
+                            "pipewire-pulse"
+                          ];
+                        }
                         ++ [
                           {
                             type = "bind";