Redesign header - move search bar into main navigation

- Move search input with tokens into center of header
- Remove tabs (Search, Catalog, Orders, Seller)
- Icons (bot, globe, user) remain on right side
- Chips for filter selection below input
- Delete GlobalSearchBar.vue and UnifiedSearchBar.vue
- Share searchQuery via useState across composable calls
- Simplify main page to just show hero

app/pages/index.vue

@@ -1,29 +1,7 @@
 <template>
-  <CatalogPage
-    :items="[]"
-    :loading="false"
-    :total-count="0"
-    :with-map="false"
-    map-id="main-catalog-map"
-  >
-    <template #searchBar>
-      <UnifiedSearchBar
-        :active-tokens="activeTokens"
-        :available-chips="availableChips"
-        :select-mode="selectMode"
-        :search-query="searchQuery"
-        @start-select="startSelect"
-        @cancel-select="cancelSelect"
-        @edit-token="editFilter"
-        @remove-token="removeFilter"
-        @update:search-query="searchQuery = $event"
-      />
-    </template>
-
-    <template #empty>
-      <CatalogHero @start-select="startSelect" />
-    </template>
-  </CatalogPage>
+  <div class="flex-1 flex items-center justify-center py-8">
+    <CatalogHero @start-select="startSelect" />
+  </div>
 </template>
 
 <script setup lang="ts">
@@ -31,14 +9,5 @@ definePageMeta({
   layout: 'topnav'
 })
 
-const {
-  selectMode,
-  searchQuery,
-  activeTokens,
-  availableChips,
-  startSelect,
-  cancelSelect,
-  removeFilter,
-  editFilter
-} = useCatalogSearch()
+const { startSelect } = useCatalogSearch()
 </script>