feat: flip routing — customer portal at /, admin at /admin (#57)

* feat: flip routing — customer portal at /, admin at /admin

Move all admin dashboard routes under /admin prefix and mount the
customer portal at root (/). This gives customers clean, shareable
URLs while staff bookmark /admin.

- Admin routes: /admin, /admin/clients, /admin/services, etc.
- Customer portal: / (root)
- Admin nav "Customer Portal" link points to / for staff preview
- Updated tests for new route structure and fixed React 19 act compat

Closes #56

Co-Authored-By: Paperclip <noreply@paperclip.ing>

* fix(e2e): update tests for routing flip — admin at /admin, portal at /

All E2E tests now use /admin prefix for admin routes (clients, services,
staff, invoices, reports, book). Adds customer portal smoke test at /.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* fix(e2e): use specific locator for customer portal test

getByText('Paws & Reflect') matched 3 elements causing strict mode
violation. Scope to navigation role for unique match.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Groom Book CTO <cto@groombook.dev>
Co-authored-by: Paperclip <noreply@paperclip.ing>
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

apps/web/src/__tests__/App.test.tsx

@@ -1,5 +1,5 @@
 import { describe, it, expect, vi, beforeEach } from "vitest";
-import { render, screen, within, act } from "@testing-library/react";
+import { render, screen, within } from "@testing-library/react";
 import { MemoryRouter } from "react-router-dom";
 import { App } from "../App.js";
 
@@ -11,30 +11,28 @@ beforeEach(() => {
   } as unknown as Response);
 });
 
-async function renderApp(route = "/") {
-  await act(async () => {
-    render(
-      <MemoryRouter initialEntries={[route]}>
-        <App />
-      </MemoryRouter>
-    );
-  });
+function renderApp(route = "/admin") {
+  render(
+    <MemoryRouter initialEntries={[route]}>
+      <App />
+    </MemoryRouter>
+  );
   return screen.getByRole("navigation");
 }
 
 describe("App navigation", () => {
-  it("renders the Groom Book brand", async () => {
-    const nav = await renderApp();
+  it("renders the Groom Book brand", () => {
+    const nav = renderApp();
     expect(within(nav).getByText("Groom Book")).toBeInTheDocument();
   });
 
-  it("renders the Book CTA button", async () => {
-    const nav = await renderApp();
+  it("renders the Book CTA button", () => {
+    const nav = renderApp();
     expect(within(nav).getByText("Book")).toBeInTheDocument();
   });
 
-  it("renders all primary nav links", async () => {
-    const nav = await renderApp();
+  it("renders all primary nav links", () => {
+    const nav = renderApp();
     const expectedLinks = [
       "Appointments",
       "Clients",
@@ -49,10 +47,20 @@ describe("App navigation", () => {
     });
   });
 
-  it("highlights the active route link", async () => {
-    const nav = await renderApp("/clients");
+  it("highlights the active route link", () => {
+    const nav = renderApp("/admin/clients");
     const clientsLink = within(nav).getByText("Clients");
     // Active links use fontWeight 600
     expect(clientsLink).toHaveStyle({ fontWeight: "600" });
   });
+
+  it("renders customer portal at root", () => {
+    render(
+      <MemoryRouter initialEntries={["/"]}>
+        <App />
+      </MemoryRouter>
+    );
+    // Customer portal should render at root - no admin nav present
+    expect(screen.queryByText("Groom Book")).not.toBeInTheDocument();
+  });
 });