feat(shell): manage herdr agent integrations

.agents

@@ -0,0 +1 @@
+.pi

AGENTS.md

@@ -105,3 +105,8 @@
   Different game installs can contain compiled scripts with the same internal path.
 - Clew owns Ren'Py extraction, preparation, and compiled-script AST export. Ariadne owns analysis over Clew-produced data.
 - Bazel Python targets require `PYTHON_TOOLCHAIN_ROOT` to point at a Python installation root.
+- When checking whether a package exists in nixpkgs, check both this repository's pinned nixpkgs inputs
+  and the relevant current upstream channel. A package can exist on current `nixos-unstable` while being
+  absent from the pinned revision or from a different branch such as `nixpkgs-unstable`.
+- OMP does not discover project skills from `.pi/skills`.
+  Put skills shared by Pi and OMP under `.agents/skills`, or configure OMP's `skills.customDirectories`.

configs/nixos/modules/shell/herdr.nix

@@ -10,12 +10,29 @@ let
   user = config.user.name;
 in
 {
-  options.modules.shell.herdr.enable = lib.mkEnableOption "Herdr, a terminal multiplexer for coding agents";
+  options.modules.shell.herdr = {
+    enable = lib.mkEnableOption "Herdr, a terminal multiplexer for coding agents";
+
+    integrations = {
+      pi.enable = lib.mkOption {
+        type = lib.types.bool;
+        default = config.modules.shell.pi.enable;
+        description = "Whether to install Herdr's Pi agent-state integration.";
+      };
+
+      omp.enable = lib.mkOption {
+        type = lib.types.bool;
+        default = config.modules.shell.omp.enable;
+        description = "Whether to install Herdr's OMP agent-state integration.";
+      };
+    };
+  };
 
   config = lib.mkIf cfg.enable {
     registry.shell-shortcut.${config.networking.hostName}.hs = "herdr --session";
 
-    home-manager.users.${user} = {
+    home-manager.users.${user} = lib.mkMerge [
+      {
         home.packages = [ pkgs.herdr ];
 
         xdg.configFile."herdr/config.toml".text = ''
@@ -42,6 +59,19 @@ in
           [experimental]
           kitty_graphics = true
         '';
+      }
+      (lib.mkIf cfg.integrations.pi.enable {
+        home.file.".pi/agent/extensions/herdr-agent-state.ts" = {
+          source = "${pkgs.herdr.src}/src/integration/assets/pi/herdr-agent-state.ts";
+          force = true;
         };
+      })
+      (lib.mkIf cfg.integrations.omp.enable {
+        home.file.".omp/agent/extensions/herdr-omp-agent-state.ts" = {
+          source = "${pkgs.herdr.src}/src/integration/assets/omp/herdr-agent-state.ts";
+          force = true;
+        };
+      })
+    ];
   };
 }