feat: add toolbox contract shell and testkit

vitest.config.ts

@@ -0,0 +1,26 @@
+import { fileURLToPath } from "node:url";
+
+import { defineConfig } from "vitest/config";
+
+const fromRoot = (path: string): string =>
+  fileURLToPath(new URL(path, import.meta.url));
+
+export default defineConfig({
+  resolve: {
+    alias: {
+      "@add-ideas/toolbox-contract": fromRoot(
+        "./packages/contract/src/index.ts",
+      ),
+      "@add-ideas/toolbox-shell-react": fromRoot(
+        "./packages/shell-react/src/index.ts",
+      ),
+    },
+  },
+  test: {
+    environment: "jsdom",
+    setupFiles: [fromRoot("./vitest.setup.ts")],
+    coverage: {
+      reporter: ["text", "html"],
+    },
+  },
+});