feat(v1): add basic backend and frontend

frontend/src/App.test.jsx

@@ -0,0 +1,15 @@
+import { render, screen } from "@testing-library/react";
+import App from "./App.jsx";
+
+vi.mock("react-quick-pinch-zoom", () => ({
+  default: ({ children }) => <div>{children}</div>
+}));
+
+describe("App", () => {
+  it("renders the processing studio immediately", () => {
+    render(<App />);
+    expect(screen.getByText("Spatial Image Enhancer Pro")).toBeInTheDocument();
+    expect(screen.getAllByText("Original").length).toBeGreaterThan(0);
+    expect(screen.getAllByText("Processed").length).toBeGreaterThan(0);
+  });
+});