Add overlay for nixpkgs.

helpers.nix

@@ -11,31 +11,104 @@ with inputs.nixpkgs.lib; {
     user ? "fern",
     extraModules ? [],
   }: let
+    system = platform;
+    secrets = builtins.toString inputs.secrets;
+
+    pull-requests = {
+      fluffychat = import nixpkgs-pr-fluffychat {
+        inherit system;
+        overlays = [
+          (final: prev: {
+            fluffychat = prev.fluffychat.overrideAttrs (prevAttrs: rec {
+              desktopItems = [
+                ((builtins.elemAt prevAttrs.desktopItems 0).override {startupWMClass = "fluffychat";})
+              ];
+            });
+          })
+        ];
+      };
+
+      feishin = import nixpkgs-pr-feishin {
+        inherit system;
+        overlays = [
+          (final: prev: {
+            feishin = prev.feishin.overrideAttrs (prevAttrs: rec {
+              pname = "feishin";
+              version = "0.18.0";
+
+              src = prev.fetchFromGitHub {
+                owner = "jeffvli";
+                repo = "feishin";
+                rev = "v${version}";
+                hash = "sha256-4gcS7Vd7LSpEByO2Hlk6nb8V2adBPh5XwWGCu2lwOA4=";
+              };
+
+              pnpmDeps = prev.pnpm_10.fetchDeps {
+                inherit pname version src;
+                hash = "sha256-1MGxrUcfvazxAubaYAsQuulUKm05opWOIC7oaLzjr7o=";
+              };
+            });
+          })
+        ];
+      };
+    };
+
+    userPackages = final: prev: {
+      # WebOne HTTP proxy.
+      webone = prev.pkgs.callPackage ./packages/webone {};
+      # Yazi Gruvbox theme.
+      yazi-flavour-gruvbox-dark = prev.pkgs.callPackage ./packages/yazi-flavour-gruvbox {};
+      # Latest FluffyChat.
+      fluffychat = pull-requests.fluffychat.fluffychat;
+      # Latest Feishin.
+      feishin = pull-requests.feishin.feishin;
+      # PrismLauncher with Temurin JRE.
+      prismlauncher = prev.prismlauncher.override {
+        jdks = [
+          prev.pkgs.temurin-jre-bin
+        ];
+      };
+    };
+
+    pkgs = import nixpkgs {
+      inherit system;
+      config = {
+        allowUnfree = true;
+        permittedInsecurePackages = [
+          "dotnet-sdk-6.0.428"
+          "dotnet-runtime-6.0.36"
+        ];
+      };
+      overlays = [
+        userPackages
+      ];
+    };
+
+    deployPkgs = import nixpkgs {
+      inherit system;
+      overlays = [
+        deploy-rs.overlays.default
+        (self: super: {
+          deploy-rs = {
+            inherit (pkgs) deploy-rs;
+            lib = super.deploy-rs.lib;
+          };
+        })
+      ];
+    };
   in
     {
       nixosConfigurations.${hostname} = nixosSystem {
-        system = platform;
-        pkgs = import nixpkgs {
-          inherit system;
-          config = {
-            allowUnfree = true;
-            permittedInsecurePackages = [
-              "dotnet-sdk-6.0.428"
-              "dotnet-runtime-6.0.36"
-            ];
-          };
-          overlays = [(import ./overlay.nix inputs)];
-        };
+        inherit system pkgs;
 
         specialArgs = {
           inherit
-            nixpkgs
             hostname
             platform
             suite
             user
+            secrets
             ; # Inherit variables.
-          secrets = builtins.toString inputs.secrets;
         };
 
         modules =
@@ -49,13 +122,15 @@ with inputs.nixpkgs.lib; {
           ++ extraModules;
       };
     }
-    // optionalAttrs (suite != "desktop") {
+    // optionalAttrs ((suite == "server")
+      || (suite == "vm")
+      || (suite == "lxc")) {
       deploy.nodes.${hostname} = {
         hostname = "${hostname}.local";
         profiles.system = {
           user = "root";
           sshUser = user;
-          path = pkgs.deploy-rs.deploy-rs.lib.activate.nixos self.nixosConfigurations.${hostname};
+          path = deployPkgs.deploy-rs.lib.activate.nixos self.nixosConfigurations.${hostname};
         };
       };
     };