feat(catalog): implement step-by-step navigation for offers and suppliers

- Transform offers/index.vue to show products list with sparkline charts
- Create nested routes for offers: /offers → /offers/[productId] → /offers/[productId]/[hubId]
- Create nested routes for suppliers: /suppliers → /suppliers/[supplierId] → /suppliers/[supplierId]/[productId] → /suppliers/[supplierId]/[productId]/[hubId]
- Add OffersBreadcrumbs and SuppliersBreadcrumbs components for navigation
- Update HubCard to accept custom linkTo prop
- Key difference: Suppliers calculation uses FindRoutes (single source), Offers uses FindProductRoutes (all sources)

app/components/catalog/OffersBreadcrumbs.vue

@@ -0,0 +1,51 @@
+<template>
+  <div class="breadcrumbs text-sm">
+    <ul>
+      <li v-for="(crumb, index) in breadcrumbs" :key="index">
+        <NuxtLink v-if="crumb.to" :to="crumb.to" class="hover:text-primary">
+          {{ crumb.label }}
+        </NuxtLink>
+        <span v-else class="text-base-content">{{ crumb.label }}</span>
+      </li>
+    </ul>
+  </div>
+</template>
+
+<script setup lang="ts">
+const props = defineProps<{
+  productId?: string
+  productName?: string
+  hubId?: string
+  hubName?: string
+}>()
+
+const localePath = useLocalePath()
+const { t } = useI18n()
+
+const breadcrumbs = computed(() => {
+  const crumbs: Array<{ label: string; to?: string }> = []
+
+  // Products list
+  crumbs.push({
+    label: t('breadcrumbs.products', 'Products'),
+    to: localePath('/catalog/offers')
+  })
+
+  // Product
+  if (props.productId) {
+    crumbs.push({
+      label: props.productName || `#${props.productId.slice(0, 8)}...`,
+      to: props.hubId ? localePath(`/catalog/offers/${props.productId}`) : undefined
+    })
+  }
+
+  // Hub
+  if (props.hubId) {
+    crumbs.push({
+      label: props.hubName || `#${props.hubId.slice(0, 8)}...`
+    })
+  }
+
+  return crumbs
+})
+</script>