refactor(nixos/desktop): move hyprlock config to nixos module

modules/home/desktop/lockscreen/hyprlock/default.nix

@@ -0,0 +1,49 @@
+{ osConfig, lib, ... }:
+let
+  inherit (lib) singleton mkIf;
+  cfg = osConfig.desktop.lockscreen.hyprlock;
+in
+{
+  config = mkIf cfg.enable {
+    assertions = singleton {
+      assertion = osConfig.security.pam.services ? hyprlock;
+      message = "You must add hyprlock to osConfig.security.pam.services.";
+    };
+    home.sessionVariables.LOCKSCREEN = "hyprlock";
+    programs.hyprlock = {
+      enable = true;
+      settings = {
+        general.hide_cursor = true;
+        general.ignore_empty_input = true;
+
+        background = {
+          blur_passes = 5;
+          blur_size = 5;
+        };
+
+        label = {
+          text = ''hi, $USER.'';
+          font_size = 32;
+          halign = "center";
+          valign = "center";
+          position = "0, 0";
+          zindex = 1;
+          shadow_passes = 5;
+          shadow_size = 5;
+        };
+
+        input-field = {
+          fade_on_empty = true;
+          size = "200, 45";
+          halign = "center";
+          valign = "center";
+          position = "0, -5%";
+          placeholder_text = "";
+          zindex = 1;
+          shadow_passes = 5;
+          shadow_size = 5;
+        };
+      };
+    };
+  };
+}