Implement unified catalog search with token-based filtering

- Add useCatalogSearch composable for managing unified search state
- Add UnifiedSearchBar component with token chips for filters
- Add CatalogHero component for empty/landing state
- Create grid components for each display mode:
  - CatalogGridProducts, CatalogGridSuppliers, CatalogGridHubs
  - CatalogGridHubsForProduct, CatalogGridProductsFromSupplier
  - CatalogGridProductsInHub, CatalogGridOffers
- Add unified catalog page at /catalog with query params
- Remove SubNavigation from catalog section (kept for other sections)
- Update all links to use new unified catalog paths
- Delete old nested catalog pages (offers/suppliers/hubs flows)
- Add i18n translations for catalog section

app/components/catalog/CatalogHero.vue

@@ -0,0 +1,42 @@
+<template>
+  <div class="flex flex-col items-center justify-center min-h-[60vh] text-center px-4">
+    <h1 class="text-4xl font-bold mb-4">{{ t('catalog.hero.title') }}</h1>
+    <p class="text-lg text-base-content/70 mb-8 max-w-lg">
+      {{ t('catalog.hero.subtitle') }}
+    </p>
+
+    <div class="flex flex-wrap justify-center gap-4">
+      <button
+        class="btn btn-lg btn-primary gap-2"
+        @click="$emit('start-select', 'product')"
+      >
+        <Icon name="lucide:package" size="24" />
+        {{ t('catalog.filters.product') }}
+      </button>
+
+      <button
+        class="btn btn-lg btn-outline gap-2"
+        @click="$emit('start-select', 'supplier')"
+      >
+        <Icon name="lucide:factory" size="24" />
+        {{ t('catalog.filters.supplier') }}
+      </button>
+
+      <button
+        class="btn btn-lg btn-outline gap-2"
+        @click="$emit('start-select', 'hub')"
+      >
+        <Icon name="lucide:map-pin" size="24" />
+        {{ t('catalog.filters.hub') }}
+      </button>
+    </div>
+  </div>
+</template>
+
+<script setup lang="ts">
+defineEmits<{
+  (e: 'start-select', type: string): void
+}>()
+
+const { t } = useI18n()
+</script>