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/HubCard.vue

@@ -1,7 +1,7 @@
 <template>
   <component
     :is="linkable ? NuxtLink : 'div'"
-    :to="linkable ? localePath(`/catalog/hubs/${hub.uuid}`) : undefined"
+    :to="linkable ? resolvedLink : undefined"
     class="block"
     :class="{ 'cursor-pointer': selectable }"
     @click="selectable && $emit('select')"
@@ -47,6 +47,7 @@ const props = defineProps<{
   hub: Hub
   selectable?: boolean
   isSelected?: boolean
+  linkTo?: string
 }>()
 
 defineEmits<{
@@ -57,7 +58,8 @@ defineEmits<{
 const localePath = useLocalePath()
 const { t } = useI18n()
 
-const linkable = computed(() => !props.selectable && props.hub.uuid)
+const linkable = computed(() => !props.selectable && (props.linkTo || props.hub.uuid))
+const resolvedLink = computed(() => props.linkTo || localePath(`/catalog/hubs/${props.hub.uuid}`))
 
 // ISO code to emoji flag
 const isoToEmoji = (code: string): string => {