fix(admin): theme, American English, and inventory/reservation tooling (#27)

Seven reported items, of which the first four had two root causes.

The active tab was invisible in dark mode because colorPrimary was
hardcoded to #1a1a1a in both themes. The accent now inverts with the
theme, and colorTextLightSolid inverts with it, or a near-white accent
would get antd's default white label and disappear.

The Category tab, Tag tab, and item-form category selector ignored the
theme entirely. antd declares main: lib/index.js and module: es/index.js,
so importing from 'antd' resolves to the ES build while 'antd/lib/...'
loads the CommonJS one — two copies, two React contexts, and no
ConfigProvider for anything deep-imported. Switching those files to
antd/es/* keeps the deep-import convention and shares the instance. This
was introduced by my own use of the lib path; es is correct under Vite.
Two storefront components had the same latent bug.

"Colour" is now "Color".

The Customers tab shows how many items each customer is holding, as a
link opening the item list with a Release button. Release mirrors the
customer's own cart removal — drop the cart row, return the item to
available, guarded on 'reserved' so it can never resurrect a sold item —
and deliberately sends no email about an action the customer did not
take. The count is a subquery rather than another join, which would have
multiplied rows and inflated order_count and total_spent_cents.

The Inventory tab filters by category, tags, price, and status, reusing
the storefront's parser and query builder so the two cannot drift.
Reserved is one option in a Status filter rather than a standalone toggle.

Also fixes two defects the screenshots exposed: the reserved-count link
bubbled to the row handler and opened the customer drawer behind the
dialog, and .admin-category-node had no CSS at all, so the tree node name,
item count, and actions ran together as one string.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

backend/src/routes/admin.ts

@@ -5,6 +5,8 @@ import { randomUUID } from 'crypto';
 import { PoolClient } from 'pg';
 import { pool } from '../db';
 import { ADMIN_ITEM_SELECT } from '../itemSelect';
+import { asyncRoute } from '../asyncRoute';
+import { parseItemFilters, buildItemFilterSql, FilterError } from '../itemFilters';
 import { tagColorFor } from '../utils';
 
 const router = Router();
@@ -111,10 +113,25 @@ async function setItemTags(client: PoolClient, itemId: number, tagIds: number[])
   }
 }
 
-router.get('/items', async (_req: Request, res: Response) => {
-  const { rows } = await pool.query(`${ADMIN_ITEM_SELECT} ORDER BY i.created_at DESC`);
+router.get('/items', asyncRoute(async (req: Request, res: Response) => {
+  // Same parser and query builder as the storefront, so admin filtering cannot
+  // drift from what customers see. The one addition is `status`, which is how
+  // the Inventory tab surfaces Reserved.
+  let filters;
+  try {
+    filters = parseItemFilters(req.query as Record<string, unknown>);
+  } catch (err) {
+    if (err instanceof FilterError) {
+      return res.status(400).json({ error: err.message });
+    }
+    throw err;
+  }
+
+  const { clauses, params } = buildItemFilterSql(filters, 1);
+  const where = clauses.length ? `WHERE ${clauses.join(' AND ')}` : '';
+  const { rows } = await pool.query(`${ADMIN_ITEM_SELECT} ${where} ORDER BY i.created_at DESC`, params);
   res.json(rows);
-});
+}));
 
 router.post('/items', uploadImages, async (req: Request, res: Response) => {
   const { name, description, price } = req.body;