frontend/src/admin/Admin.tsx

@@ -1,6 +1,6 @@
 import { useCallback, useEffect, useRef, useState } from 'react';
 import {
-  Layout, Table, Button, Form, Input, InputNumber, Upload, Modal,
+  Layout, Table, Button, Drawer, Form, Input, InputNumber, Upload, Modal,
   Space, Tag, Typography, Switch, message, Image as AntImage, theme, Tabs,
   Select
 } from 'antd';
@@ -20,6 +20,7 @@ import Settings from './Settings';
 import Categories from './Categories';
 import Tags from './Tags';
 import CategoryTreeSelect from './CategoryTreeSelect';
+import ItemCard from '../components/ItemCard';
 import InventoryFilters from './InventoryFilters';
 import { ItemFilters, EMPTY_FILTERS } from '../filters';
 
@@ -34,6 +35,10 @@ function Inventory() {
   const [items, setItems] = useState<Item[]>([]);
   const [modalOpen, setModalOpen] = useState(false);
   const [editingItem, setEditingItem] = useState<Item | null>(null);
+  // The item whose storefront appearance is being previewed, or null when the
+  // panel is closed. Holds the row object itself — admin and storefront share
+  // one Item type, so there is nothing to convert and nothing to drift.
+  const [previewItem, setPreviewItem] = useState<Item | null>(null);
   const [form] = Form.useForm();
   const [fileList, setFileList] = useState<UploadFile[]>([]);
   const [description, setDescription] = useState<string>('');
@@ -181,7 +186,17 @@ function Inventory() {
           </span>
         ) : null
     },
-    { title: 'Name', dataIndex: 'name' },
+    {
+      title: 'Name',
+      dataIndex: 'name',
+      // A button rather than a clickable cell so it is reachable by keyboard
+      // and announces itself as an action.
+      render: (name: string, item: Item) => (
+        <Button type="link" style={{ padding: 0, height: 'auto', textAlign: 'left' }} onClick={() => setPreviewItem(item)}>
+          {name}
+        </Button>
+      )
+    },
     {
       title: 'Category',
       dataIndex: 'category_name',
@@ -283,6 +298,26 @@ function Inventory() {
           </Form>
         </div>
       </Modal>
+
+      {/* The real storefront card, rendered inert. Width is pinned to what the
+          storefront grid actually gives a card at its widest column, so the
+          proportions here match what a customer sees rather than stretching to
+          fill the drawer. */}
+      <Drawer
+        title={previewItem ? `Preview: ${previewItem.name}` : 'Preview'}
+        open={previewItem !== null}
+        onClose={() => setPreviewItem(null)}
+        width={420}
+        destroyOnHidden
+      >
+        {previewItem && (
+          <div style={{ maxWidth: 340, margin: '0 auto' }}>
+            {/* onChanged never fires: every handler that would call it is
+                short-circuited by `preview`. */}
+            <ItemCard item={previewItem} onChanged={() => undefined} preview />
+          </div>
+        )}
+      </Drawer>
     </div>
   );
 }

frontend/src/components/ItemCard.tsx

@@ -16,9 +16,21 @@ const { Text, Title } = Typography;
 interface Props {
   item: Item;
   onChanged: () => void;
+  // Render exactly as the storefront does, but inert. The admin's inventory
+  // preview uses this: the cart and favorites providers wrap the whole app, so
+  // without it an admin looking at an item could add their own stock to their
+  // own cart — and on a one-of-a-kind catalogue that reserves the item and
+  // takes it off sale.
+  //
+  // Deliberately not `disabled` on the buttons. A disabled antd button renders
+  // in a different colour with a different cursor and no hover, and the entire
+  // point of the preview is to show what a customer will actually see. The
+  // controls keep their normal appearance and their correct state for the
+  // item's status; only the handlers stop.
+  preview?: boolean;
 }
 
-export default function ItemCard({ item, onChanged }: Props) {
+export default function ItemCard({ item, onChanged, preview = false }: Readonly<Props>) {
   const carouselRef = useRef<CarouselRef>(null);
   const [authModalOpen, setAuthModalOpen] = useState(false);
   const [adding, setAdding] = useState(false);
@@ -48,6 +60,7 @@ export default function ItemCard({ item, onChanged }: Props) {
   }
 
   function handleAddClick() {
+    if (preview) return;
     // Until the session has resolved, `customer` is null for a signed-in
     // visitor too, and prompting them to sign in again would be wrong.
     if (authLoading) return;
@@ -104,6 +117,7 @@ export default function ItemCard({ item, onChanged }: Props) {
   }
 
   function handleFavoriteClick() {
+    if (preview) return;
     if (authLoading) return;
     if (!customer) {
       setPendingAction('favorite');

frontend/tests/e2e/admin-item-preview.spec.ts

@@ -0,0 +1,84 @@
+import { test, expect } from './fixtures';
+
+const suffix = () => `p${Date.now().toString(36)}${Math.random().toString(36).slice(2, 7)}`;
+
+async function createItem(page: import('@playwright/test').Page, name: string, price: string) {
+  const created = await page.request.post('/api/admin/items', {
+    multipart: { name, description: 'A preview subject', price, category_id: '', tags: '[]' }
+  });
+  expect(created.ok()).toBeTruthy();
+  return (await created.json()).id as number;
+}
+
+test.describe('Admin item preview', () => {
+  test('opens the storefront card from the item name', async ({ page }) => {
+    const name = `Preview ${suffix()}`;
+    await createItem(page, name, '42');
+
+    await page.goto('/admin');
+    await page.getByRole('button', { name }).click();
+
+    const drawer = page.getByRole('dialog', { name: `Preview: ${name}` });
+    await expect(drawer).toBeVisible();
+
+    // The card itself, not just an empty panel: the storefront renders the
+    // price formatted from cents, so this only passes if ItemCard rendered.
+    await expect(drawer.getByText('$42.00')).toBeVisible();
+  });
+
+  // The claim the preview has to make: it looks live, and it is not. The
+  // buttons must keep their normal appearance rather than being disabled,
+  // because showing a customer's view is the entire purpose of the panel.
+  test('shows the Add to Cart button in its normal enabled state', async ({ page }) => {
+    const name = `Preview ${suffix()}`;
+    await createItem(page, name, '15');
+
+    await page.goto('/admin');
+    await page.getByRole('button', { name }).click();
+
+    const drawer = page.getByRole('dialog', { name: `Preview: ${name}` });
+    const addToCart = drawer.getByRole('button', { name: 'Add to Cart' });
+
+    await expect(addToCart).toBeVisible();
+    await expect(addToCart).toBeEnabled();
+  });
+
+  // The assertion that matters, and the one a reviewer cannot make by looking
+  // at the screen. Signed out, a real Add to Cart opens the sign-in prompt
+  // before it can add anything — so if that modal never appears, the handler
+  // short-circuited before reaching any of its real work.
+  test('does not act when the preview card is clicked', async ({ page }) => {
+    const name = `Preview ${suffix()}`;
+    await createItem(page, name, '99');
+
+    await page.goto('/admin');
+    await page.getByRole('button', { name }).click();
+
+    const drawer = page.getByRole('dialog', { name: `Preview: ${name}` });
+    await drawer.getByRole('button', { name: 'Add to Cart' }).click();
+
+    // Nothing succeeded and nothing prompted.
+    await expect(page.getByText('Added to cart')).toHaveCount(0);
+    await expect(page.getByRole('dialog', { name: /sign in/i })).toHaveCount(0);
+
+    // And the drawer is still simply sitting there, unchanged.
+    await expect(drawer).toBeVisible();
+    await expect(drawer.getByRole('button', { name: 'Add to Cart' })).toBeEnabled();
+  });
+
+  // The storefront card must stay live where it is actually used, or this
+  // change would have quietly broken buying things.
+  test('leaves the real storefront card working', async ({ page }) => {
+    const name = `Live ${suffix()}`;
+    await createItem(page, name, '20');
+
+    await page.goto('/');
+    const card = page.locator('.ant-card').filter({ hasText: name });
+    await expect(card).toBeVisible();
+
+    await card.getByRole('button', { name: 'Add to Cart' }).click();
+
+    // Signed out, the real card prompts for sign-in — proof the handler ran.
+    await expect(page.getByRole('dialog')).toBeVisible();
+  });
+});