tested and confirms it works

modules/archive-installs.nix

@@ -1,4 +1,4 @@
-{ pkgs, lib, ... }:
+{ pkgs, lib, config, ... }:
 
 let
   cfg = config.archiveApps;
@@ -30,12 +30,12 @@ let
     '';
 in
 {
-  optiosn.archiveApps = lib.mkOption {
-    type = lib.types.typesOf (lib.types.attrsOf lib.types.str);
+  options.archiveApps = lib.mkOption {
+    type = lib.types.listOf (lib.types.attrsOf lib.types.str);
     default = [ ];
     description = "Apps distributed as .zip archives to install into /Applications";
-  }
+  };
 
-  system.activationScripts.postActivation.text =
+  config.system.activationScripts.postActivation.text =
     lib.concatMapStringsSep "\n" appScript cfg;
 }