feat(nixos): build vendored pi

configs/nixos/modules/shell/pi/default.nix

@@ -11,12 +11,10 @@ let
   cfg = config.modules.shell.pi;
   user = config.user.name;
   piDir = "${config.users.users.${user}.home}/.pi/agent";
-  patchedPi = pkgs.pi-coding-agent.overrideAttrs (old: {
-    patches = (old.patches or [ ]) ++ [
-      ./patches/pi-project-resource-ancestors.patch
-      ./patches/pi-tool-lookup-validation.patch
-    ];
-  });
+  vendoredPi = pkgs.pi-coding-agent.overrideAttrs {
+    src = ../../../../../third_party/pi;
+    patches = [ ];
+  };
 in
 {
   options.modules.shell.pi = {
@@ -28,7 +26,7 @@ in
     home-manager.users.${user} = {
       programs.pi-coding-agent = {
         enable = true;
-        package = patchedPi;
+        package = vendoredPi;
 
         settings = {
           defaultProvider = "openai-codex";