refactor(waybar): register owned modules

configs/nixos/modules/desktop/apps/obsidian.nix

@@ -2,6 +2,7 @@
   config,
   lib,
   pkgs,
+  util,
   ...
 }:
 # Obsidian as the desktop note-taking vault.
@@ -17,7 +18,7 @@ in
 
     registry.window-icon.${config.networking.hostName}.obsidian = {
       class = "obsidian";
-      icon = "f02d";
+      icon = util.glyph "f02d";
     };
   };
 }