feat: clean up agent config

modules/capabilities/ai/_assets.nix

@@ -1,8 +1,6 @@
 { pkgs }:
 let
   sources = import ./_sources.nix { inherit pkgs; };
-  json = pkgs.formats.json { };
-  ponytailVersion = "4.9.0";
   context7Headers = pkgs.writeShellScript "context7-http-headers" ''
     set -euo pipefail
     CONTEXT7_KEY_FILE="''${XDG_CONFIG_HOME:-$HOME/.config}/context7/api-key"
@@ -25,32 +23,7 @@ let
   };
 in
 {
-  inherit sources ponytailVersion context7Headers;
-  inherit codexHooks;
-  codexCache = ".codex/plugins/cache/nix-managed/ponytail/${ponytailVersion}";
-  marketplace = pkgs.runCommand "ai-marketplace" { } ''
-    mkdir -p "$out/.agents/plugins" "$out/plugins"
-    ln -s ${sources.ponytail} "$out/plugins/ponytail"
-    cp ${
-      json.generate "ai-marketplace.json" {
-        name = "nix-managed";
-        plugins = [
-          {
-            name = "ponytail";
-            source = {
-              source = "local";
-              path = "./plugins/ponytail";
-            };
-            policy = {
-              installation = "AVAILABLE";
-              authentication = "ON_INSTALL";
-            };
-            category = "Productivity";
-          }
-        ];
-      }
-    } "$out/.agents/plugins/marketplace.json"
-  '';
+  inherit context7Headers codexHooks;
   skills = {
     context7-mcp = ../skills/context7-mcp;
     nixos-maintainer = ../skills/nixos-maintainer;