feat(client): the whole client half (phase 3, slice 3)

The 35 files behind twelve public pages, seven admin views, two player views
and three core-page extensions, ported onto `window.__rg`. Every one of them
imports exactly the seven kit members plus `lib/format.js`, which is the
finding §2.7.1 predicted and this confirms.

`client/src/core.js` is the port mechanism, and unlike the server's it is a
plain read: `window.__rg` is published before any module chunk evaluates, so
there is no gap to defer around and a ported component keeps its ordinary
import shape. `client/src/api.js` rebuilds the UO namespaces over the request
primitive — same URLs, because §1.2 freezes the API surface.

SPA paths changed and API paths did not. `/site/shard` is `/uo/shard`, and the
admin paths lost their now-redundant `shard-` prefixes (`/admin/uo/ops`), a
clean break being the only moment that is free.

`shim/rg.js` becomes the single reader of the global, so the "core did not
publish its dependencies" message is reachable from whichever module the
bundler happens to touch first rather than from whichever one is imported
first — a guarantee that used to last until someone sorted the imports.

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

client/src/routes/public/MarketVendor.jsx

@@ -0,0 +1,99 @@
+import { Link, useParams } from 'react-router-dom'
+import api from '../../api.js'
+import { EmptyState, ErrorState, Loading, PageHeader, PublicLayout, useAsync } from '../../core.js'
+
+// One player vendor: where to find it and everything it is selling.
+//
+// The page a search result points at. Two states it has to render honestly and
+// which the search list cannot (docs/link/v3.md §8):
+//
+//   • `truncated` — the shop holds more than the shard publishes per frame. A
+//     commodity reseller with thousands of stacks is a real thing, and showing
+//     250 of 3,104 as if it were the whole shop would be a lie about the shard.
+//   • a gated `location` — an admin may put vendor whereabouts behind a rung, in
+//     which case there is nothing to render and the page says so rather than
+//     showing an empty coordinate.
+
+const num = (v) => (Number.isFinite(Number(v)) ? Number(v).toLocaleString() : '—')
+
+const itemLabel = (i) => i.displayName || i.name || `id ${i.itemId}`
+
+export default function MarketVendor() {
+  const { serial } = useParams()
+  const { loading, error, data } = useAsync(() => api.shard.marketVendor(serial), [serial])
+
+  if (loading) {
+    return (
+      <PublicLayout section="website">
+        <div className="shell-narrow page-body"><Loading /></div>
+      </PublicLayout>
+    )
+  }
+
+  if (error || !data) {
+    return (
+      <PublicLayout section="website">
+        <div className="shell-narrow page-body">
+          <ErrorState message="That shop is not in the index — it may have been dismissed or hidden." />
+          <p style={{ marginTop: 16 }}>
+            <Link to="/uo/market" className="sans">← Back to the marketplace</Link>
+          </p>
+        </div>
+      </PublicLayout>
+    )
+  }
+
+  const loc = data.location || null
+  const items = data.items || []
+
+  return (
+    <PublicLayout section="website">
+      <div className="shell-narrow page-body">
+        <PageHeader
+          eyebrow={data.ownerName ? `Run by ${data.ownerName}` : 'Player vendor'}
+          title={data.shopName || 'An unnamed shop'}
+          lead={
+            loc
+              ? [loc.house, loc.region, loc.map].filter(Boolean).join(' · ') +
+                (Number.isFinite(loc.x) ? ` — ${loc.x}, ${loc.y}` : '')
+              : 'This shard does not publish vendor locations.'
+          }
+        />
+
+        <p className="sans dim" style={{ fontSize: '0.78rem', margin: '-12px 0 18px' }}>
+          {data.truncated
+            ? `Showing ${num(data.count)} of ${num(data.total)} listings — this shop holds more than the shard publishes.`
+            : `${num(data.total)} listing${data.total === 1 ? '' : 's'}`}
+          {data.updatedAt ? ` · last seen ${new Date(data.updatedAt).toLocaleString()}` : ''}
+        </p>
+
+        {items.length === 0 ? (
+          <EmptyState>This shop has nothing priced for sale.</EmptyState>
+        ) : (
+          <div style={{ display: 'flex', flexDirection: 'column', gap: 6 }}>
+            {items.map((i) => (
+              <div
+                key={i.serial}
+                className="panel"
+                style={{ padding: '10px 14px', display: 'flex', gap: 12, alignItems: 'baseline' }}
+              >
+                <span className="sans" style={{ flex: 1, minWidth: 0, color: 'var(--head)', fontSize: '0.88rem' }}>
+                  {i.amount > 1 ? `${num(i.amount)} × ` : ''}
+                  {itemLabel(i)}
+                  {i.child ? <span className="dim"> · sold with its container</span> : null}
+                </span>
+                <span className="sans" style={{ flex: 'none', color: 'var(--head)', fontSize: '0.88rem' }}>
+                  {num(i.price)}
+                </span>
+              </div>
+            ))}
+          </div>
+        )}
+
+        <p style={{ marginTop: 20 }}>
+          <Link to="/uo/market" className="sans">← Back to the marketplace</Link>
+        </p>
+      </div>
+    </PublicLayout>
+  )
+}