home/hyprpaper: update attribute types

this will break keith :(

modules/factory/hyprpaper.nix

@@ -1,19 +1,22 @@
 {
-  config.flake.factory.hyprpaper =
-    { wallpaper_path
-    , monitor_names
-    ,
-    }: { config, ... }: {
-      services.hyprpaper =
-        /*
-      TODO: assert that hyprland is enabled
-        */
-        {
-          enable = true;
-          settings = {
-            preload = [ wallpaper_path ];
-            wallpaper = map (mon: "mon,${wallpaper_path}") monitor_names;
-          };
-        };
+  config.flake.factory.hyprpaper = mappings: { config
+                                             , osConfig
+                                             , lib
+                                             , ...
+                                             }: {
+    services.hyprpaper = assert osConfig.programs.hyprland.enable; {
+      enable = true;
+      settings = {
+        preload = map ({ path, ... }: path) mappings;
+        wallpaper =
+          map
+            ({ monitor
+             , path
+             , prefix ? ""
+             ,
+             }: "${monitor},${prefix}${path}")
+            mappings;
+      };
     };
+  };
 }