Apps, refactor, clean up, remove librewolf

Refactors to use app.nix for easier extension.

Removes librewolf from host, as it makes more sense on the user every
time.

nixosModules/apps/default.nix

@@ -1,12 +1,6 @@
-{ config, pkgs, lib, ... }:
-
-{
-  imports = [
-    ./games
-    ./input-remapper
-    ./librewolf
-    ./shells
-    ./syncthing
-    ./virtualbox
-  ];
+{ lib, ... }: let
+  fs = lib.fileset;
+  appFilter = {name, ...}: name == "app.nix";
+in {
+  imports = fs.toList (fs.fileFilter appFilter ./.);
 }