feat: harden portfolio and add SEO foundations

jest.setup.ts

@@ -1,5 +1,13 @@
 import "@testing-library/jest-dom";
-import "./__mocks__/resizeObserver";
+
+if (typeof global.ResizeObserver === "undefined") {
+  class ResizeObserver {
+    observe() {}
+    unobserve() {}
+    disconnect() {}
+  }
+  global.ResizeObserver = ResizeObserver as typeof global.ResizeObserver;
+}
 
 // Mock IntersectionObserver if not available in JSDOM
 if (typeof global.IntersectionObserver === "undefined") {