use jovian-nixos + fixup niri display session handling

etcnixos/common.nix

@@ -6,6 +6,7 @@
   system,
   hostname,
   inputs,
+  niri-package,
   ...
 }:
 {
@@ -33,6 +34,9 @@
 
   services.kmscon.enable = true;
 
+  # Add niri to display manager session packages
+  services.displayManager.sessionPackages = [ niri-package ];
+
   # Gamescope configuration for Steam Deck-like experience
   programs = {
     gamescope = {
@@ -45,26 +49,6 @@
     };
   };
 
-  services.greetd = {
-    enable = true;
-    settings = {
-      default_session = {
-        command = "${lib.getExe pkgs.tuigreet} --sessions /etc/xdg/wayland-sessions/ --time";
-        user = username;
-      };
-      terminal.vt = lib.mkForce 2;
-    };
-  };
-
-  environment.etc."xdg/wayland-sessions/niri-session.desktop".text = ''
-    [Desktop Entry]
-    Name=Niri Session
-    Comment=Niri Wayland compositor
-    Exec=niri-session
-    Type=Application
-    DesktopNames=niri
-  '';
-
   system.activationScripts = {
     # FIX: https://github.com/NixOS/nix/issues/2982
     "profile-channel-dummy".text = ''
@@ -97,6 +81,9 @@
     ];
   };
 
+  # allow unfree packages for jovian-nixos
+  nixpkgs.config.allowUnfree = true;
+
   # kernel options
   boot = {
     kernelPackages = pkgs.linuxPackages_latest;

etcnixos/steam.nix

@@ -25,26 +25,4 @@
     goverlay
     yad
   ];
-
-  # Create steam session script
-  environment.etc."steam-session-greetd".source = pkgs.writeShellScript "steam-session-greetd" ''
-    export STEAM_RUNTIME=1
-    export SDL_VIDEODRIVER=wayland
-    export QT_QPA_PLATFORM=wayland
-    export GDK_BACKEND=wayland
-    export XDG_CURRENT_DESKTOP=Steam
-    export XDG_SESSION_TYPE=wayland
-    exec ${pkgs.gamescope}/bin/gamescope --adaptive-sync --hdr-enabled --rt --steam -- ${pkgs.steam}/bin/steam -pipewire-dmabuf -tenfoot
-  '';
-
-  # Create system-wide session files
-  environment.etc."xdg/wayland-sessions/steam-session.desktop".text = ''
-    [Desktop Entry]
-    Name=Steam Session
-    Comment=Steam Deck-like gaming session with gamescope
-    Exec=/etc/steam-session-greetd
-    Type=Application
-    DesktopNames=steam
-  '';
-
 }

etcnixos/system-mreow.nix

@@ -34,4 +34,25 @@
   # disable framework kernel module
   # https://github.com/NixOS/nixos-hardware/issues/1330
   hardware.framework.enableKmod = false;
+
+  # Greetd display manager
+  services.greetd = {
+    enable = true;
+    settings = {
+      default_session = {
+        command = "${lib.getExe pkgs.tuigreet} --sessions /etc/xdg/wayland-sessions/ --time";
+        user = username;
+      };
+      terminal.vt = lib.mkForce 2;
+    };
+  };
+
+  environment.etc."xdg/wayland-sessions/niri-session.desktop".text = ''
+    [Desktop Entry]
+    Name=Niri Session
+    Comment=Niri Wayland compositor
+    Exec=niri-session
+    Type=Application
+    DesktopNames=niri
+  '';
 }

etcnixos/system-yarn.nix

@@ -18,6 +18,7 @@
     inputs.nixos-hardware.nixosModules.common-cpu-amd-zenpower
     inputs.impermanence.nixosModules.impermanence
     inputs.disko.nixosModules.disko
+    inputs.jovian-nixos.nixosModules.default
   ];
 
   fileSystems."/media/games" = {
@@ -58,4 +59,17 @@
   systemd.services.lactd.wantedBy = [ "multi-user.target" ];
 
   systemd.services.lactd.serviceConfig.ExecStartPre = "${lib.getExe pkgs.bash} -c \"sleep 3s\"";
+
+  jovian = {
+    devices.steamdeck.enable = false;
+    steam = {
+      enable = true;
+      autoStart = true;
+      desktopSession = "niri";
+      user = username;
+    };
+  };
+
+  # Disable gamescope from common.nix to avoid conflict with jovian-nixos
+  programs.gamescope.enable = lib.mkForce false;
 }