Add hermes

machines/fry/workspaces/hermes.nix

@@ -0,0 +1,41 @@
+{ pkgs, hostConfig, ... }:
+
+{
+  imports = [ hostConfig.inputs.hermes-agent.nixosModules.default ];
+
+  services.hermes-agent = {
+    enable = true;
+    addToSystemPackages = true;
+    container.enable = false;
+
+    # Run the daemon as the same user that owns workspace files so the agent
+    # can read/write the project tree without permission gymnastics.
+    user = "googlebot";
+    group = "users";
+    createUser = false;
+
+    extraPackages = with pkgs; [ nix git ripgrep fd jq ];
+
+    # Bind-mounted from /run/agenix/hermes-env on fry (host decrypts via agenix).
+    # Lives at /etc/... rather than /run/... because the workspace's systemd
+    # mounts a fresh tmpfs over /run at boot, which would shadow the incus mount.
+    # Codex OAuth is NOT here — it lives per-instance in /var/lib/hermes.
+    environmentFiles = [ "/etc/hermes-env" ];
+
+    settings = {
+      model = {
+        provider = "openai-codex";
+        default = "gpt-5.5";
+      };
+      toolsets = [ "all" ];
+      terminal.backend = "local";
+    };
+  };
+
+  # Daemon sets HERMES_HOME to stateDir/.hermes via the systemd unit. Setting
+  # it system-wide here makes interactive `hermes` (now running as googlebot)
+  # pick up the same auth.json that the daemon wrote.
+  environment.variables.HERMES_HOME = "/var/lib/hermes/.hermes";
+
+  environment.systemPackages = [ pkgs.codex ];
+}