refactor: centralize host and user metadata

modules/features/niri/default.nix

@@ -16,7 +16,32 @@
     };
 
   flake.modules.homeManager.niri =
-    { config, pkgs, ... }:
+    {
+      config,
+      lib,
+      pkgs,
+      ...
+    }:
+    let
+      outputs = lib.mapAttrs (
+        _: display:
+        {
+          position = {
+            x = display.x;
+            y = display.y;
+          };
+        }
+        // lib.optionalAttrs (display.primary or false) {
+          "focus-at-startup" = true;
+        }
+        // lib.optionalAttrs (display ? scale) {
+          inherit (display) scale;
+        }
+        // lib.optionalAttrs (display ? mode) {
+          inherit (display) mode;
+        }
+      ) config.meta.host.displays;
+    in
     {
       home.sessionVariables.NIXOS_OZONE_WL = "1";
 
@@ -34,6 +59,7 @@
       ];
 
       programs.niri.settings = {
+        inherit outputs;
         environment.DISPLAY = ":0";
         spawn-at-startup = [
           { command = [ "xwayland-satellite" ]; }