nixos/rumno: init module

Add a NixOS module for rumno, a visual pop-up notification manager.
The service runs as a systemd user service and registers itself as a
D-Bus notification daemon.

nixos/doc/manual/release-notes/rl-2511.section.md

@@ -205,6 +205,8 @@
 
 - [ErsatzTV](https://ersatztv.org), a personal IPTV server. Available as [services.ersatztv](#opt-services.ersatztv.enable)
 
+- [rumno](https://gitlab.com/ivanmalison/rumno), a visual pop-up notification manager. Available as [services.rumno](#opt-services.rumno.enable).
+
 ## Backward Incompatibilities {#sec-release-25.11-incompatibilities}
 
 <!-- To avoid merge conflicts, consider adding your item at an arbitrary place in the list instead. -->

nixos/modules/module-list.nix

@@ -928,6 +928,7 @@
   ./services/misc/rmfakecloud.nix
   ./services/misc/rshim.nix
   ./services/misc/rsync.nix
+  ./services/misc/rumno.nix
   ./services/misc/safeeyes.nix
   ./services/misc/sdrplay.nix
   ./services/misc/servarr/lidarr.nix

nixos/modules/services/misc/rumno.nix

@@ -0,0 +1,64 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+
+let
+  cfg = config.services.rumno;
+in
+{
+  meta.maintainers = with lib.maintainers; [ imalison ];
+
+  options.services.rumno = {
+    enable = lib.mkEnableOption "rumno visual pop-up notification manager";
+
+    package = lib.mkPackageOption pkgs "rumno" { };
+
+    extraArgs = lib.mkOption {
+      type = lib.types.listOf lib.types.str;
+      default = [ ];
+      example = [
+        "--verbose"
+        "--config"
+        "/etc/rumno/config.toml"
+      ];
+      description = ''
+        Extra command-line arguments to pass to the rumno daemon.
+      '';
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    systemd.user.services.rumno = {
+      description = "Rumno visual pop-up notification manager";
+      wantedBy = [ "graphical-session.target" ];
+      partOf = [ "graphical-session.target" ];
+      after = [ "graphical-session-pre.target" ];
+
+      serviceConfig = {
+        Type = "dbus";
+        BusName = "de.rumno.v1";
+        ExecStart = "${cfg.package}/bin/rumno daemon --foreground ${lib.escapeShellArgs cfg.extraArgs}";
+        Restart = "on-failure";
+        RestartSec = 1;
+
+        # Environment for GTK/GUI applications
+        PassEnvironment = [
+          "DISPLAY"
+          "WAYLAND_DISPLAY"
+          "XDG_RUNTIME_DIR"
+        ];
+      };
+
+      environment = {
+        # Set GTK theme environment variables if needed
+        GTK_THEME = lib.mkDefault "";
+      };
+    };
+
+    # Ensure dbus service file is installed
+    environment.systemPackages = [ cfg.package ];
+  };
+}