🔧🔐 Configure gnome keyring

modules/home/security/ssh/default.nix

···
+{
+  ...
+}:
+{
+  programs.ssh = {
+    enable = true;
+    matchBlocks = {
+      "*" = {
+        identityFile = [
+          "~/.ssh/id_ed25519"
+        ];
+      };
+    };
+  };
+}

modules/nixos/archetypes/workstation/default.nix

···
         bluetooth.enable = true;
         audio.enable = true;
         kernel.enable = true;
+        ssh.enable = true;
         nix = {
           enable = true;
           use-lix = true;

modules/nixos/system/ssh/default.nix

···
+{
+  lib,
+  self,
+  config,
+  ...
+}:
+let
+  inherit (lib) mkEnableOption mkIf;
+  inherit (self) namespace;
+
+  cfg = config.${namespace}.system.ssh;
+in
+{
+  options.${namespace}.system.ssh = {
+    enable = mkEnableOption "SSH key management and agent.";
+  };
+
+  config = mkIf cfg.enable {
+    # Enable the ssh-agent for key persistence
+    programs.ssh = {
+      extraConfig = ''
+        AddKeysToAgent yes
+      '';
+    };
+
+    # Enable Gnome keyring for session overarching key persistence
+    services.gnome.gnome-keyring.enable = true;
+  };
+}