build: use home.activation instead of just for fonts

home/apps/fonts.nix

@@ -1,4 +1,21 @@
-{pkgs, ...}: {
+{
+  config,
+  flakePath,
+  lib,
+  pkgs,
+  ...
+}: {
+  home.activation = {
+    installCustomFonts = let
+      fontDirectory =
+        if pkgs.stdenv.isDarwin
+        then "${config.home.homeDirectory}/Library/Fonts"
+        else "${config.xdg.dataHome}/fonts";
+    in
+      lib.hm.dag.entryAfter ["writeBoundary"] ''
+        install -Dm644 ${flakePath}/home/secrets/fonts/* "${fontDirectory}"
+      '';
+  };
   home.packages = with pkgs; [
     (nerdfonts.override {fonts = ["NerdFontsSymbolsOnly"];})
     victor-mono

justfile

@@ -33,15 +33,5 @@ check *args:
 switch *args:
   @just rebuild switch {{args}}
 
-# these will fail, should variables not be set
-fontdir := if os() == "macos" {
-  env_var('HOME') + "/Library/Fonts"
-} else {
-  env_var_or_default('XDG_DATA_HOME', env_var('HOME') + "/.local/share") + "/fonts"
-}
-# TODO: move these to the home.activation hook
-install-fonts:
-  install -Dm644 {{justfile_directory()}}/home/secrets/fonts/* "{{fontdir}}"
-
 fetch:
   @nix shell nixpkgs\#onefetch nixpkgs\#scc -c sh -c "onefetch --true-color never --no-bots -d lines-of-code && scc --no-cocomo ."