feat(mall): classic B2B2C PC storefront with fixed mock API layer

- Mock adapter implementing @vmall/shared ApiClient (localStorage-persisted
  cart/orders/invoices), runtime switch via mockApi flag (default on)
- Fixed bilingual mock catalog: 3-level categories, 24 products w/ SKUs,
  stores, brands, banners, floors, seckill/collective/integral, comments,
  coupons, addresses, seeded orders/shipments/invoices
- B2B2C mall shell: top bar, logo/search/cart header, dark nav + category
  mega-menu, value-prop footer, back-to-top; 1200px grid, #ca151e theme
- UI primitives replacing element-plus: carousel, pagination, breadcrumb,
  qty stepper, rating stars, modal, tabs, step bar, product card
- Pages: home floors, search (filters/sort/paging), goods detail (SKU
  picker, store rail, review tabs), cart -> checkout -> pay -> success,
  auth pages, user center (dashboard/orders/addresses/favorites/coupons/
  invoices), stores, seckill, collective, integral
- i18n split into per-domain locale modules (en+zh)
- OpenSpec change mall-pc-storefront-replica archived; all specs green

apps/mall/components/ui/Pagination.vue

@@ -0,0 +1,59 @@
+<script setup lang="ts">
+const props = defineProps<{ page: number; total: number; perPage: number }>();
+const emit = defineEmits<{ change: [page: number] }>();
+
+const pages = computed(() => Math.max(1, Math.ceil(props.total / props.perPage)));
+const window_ = computed(() => {
+  const p = props.page;
+  const n = pages.value;
+  const start = Math.max(1, Math.min(p - 2, n - 4));
+  const out: number[] = [];
+  for (let i = start; i <= Math.min(n, start + 4); i++) out.push(i);
+  return out;
+});
+
+function go(p: number): void {
+  if (p >= 1 && p <= pages.value && p !== props.page) emit("change", p);
+}
+</script>
+
+<template>
+  <nav v-if="pages > 1" class="pager">
+    <button type="button" :disabled="page <= 1" @click="go(page - 1)">{{ $t("common.prev") }}</button>
+    <button
+      v-for="p in window_"
+      :key="p"
+      type="button"
+      :class="{ on: p === page }"
+      @click="go(p)"
+    >{{ p }}</button>
+    <button type="button" :disabled="page >= pages" @click="go(page + 1)">{{ $t("common.next") }}</button>
+  </nav>
+</template>
+
+<style scoped>
+.pager {
+  display: flex;
+  justify-content: center;
+  gap: 6px;
+  margin: 30px 0;
+}
+button {
+  min-width: 34px;
+  height: 34px;
+  border: 1px solid var(--mall-line-dark);
+  background: #fff;
+  font-size: 13px;
+  cursor: pointer;
+  border-radius: var(--mall-radius);
+}
+button.on {
+  background: var(--mall-red);
+  border-color: var(--mall-red);
+  color: #fff;
+}
+button:disabled {
+  opacity: 0.4;
+  cursor: not-allowed;
+}
+</style>