test: move test program to sandbox directory

This prepares for the separation of app and sandbox tests.

Signed-off-by: Ophestra <cat@gensokyo.uk>

test/sandbox/tool/package.nix

@@ -0,0 +1,30 @@
+{
+  lib,
+  buildGoModule,
+  pkg-config,
+  util-linux,
+
+  version,
+}:
+buildGoModule rec {
+  pname = "check-sandbox";
+  inherit version;
+
+  src = builtins.path {
+    name = "${pname}-src";
+    path = lib.cleanSource ../.;
+    filter = path: type: (type == "directory") || (type == "regular" && lib.hasSuffix ".go" path);
+  };
+  vendorHash = null;
+
+  buildInputs = [ util-linux ];
+  nativeBuildInputs = [ pkg-config ];
+
+  preBuild = ''
+    go mod init git.gensokyo.uk/security/fortify/test/sandbox >& /dev/null
+  '';
+
+  postInstall = ''
+    mv $out/bin/tool $out/bin/fortify-test
+  '';
+}