Fix route conflict: move offer detail page to /offers/detail/[offerId]

- Change theme from cmyk to cupcake
- Move [offerId].vue to detail/[offerId].vue to avoid conflict with [productId]/index.vue
- Update all navigation references to use new /catalog/offers/detail/ path

app/components/catalog/OfferCard.vue

@@ -1,7 +1,7 @@
 <template>
   <component
     :is="linkable ? NuxtLink : 'div'"
-    :to="linkable ? localePath(`/catalog/offers/${offer.uuid}`) : undefined"
+    :to="linkable ? localePath(`/catalog/offers/detail/${offer.uuid}`) : undefined"
     class="block"
     :class="{ 'cursor-pointer': selectable }"
     @click="selectable && $emit('select')"