feat: add search bar and restyle catalog header matching Nueva Compra

- Replace plain title with gradient page-header (icon, title, subtitle)
- Add search field with mdi-magnify icon and real-time name filtering
- Integrate search into the header as a single sticky unit
- Add filteredItems computed for client-side product search
- Reset to page 1 on search query change
- Show distinct message when search yields no results
- Adapt pagination to work with filtered results

src/pages/catalog.vue

@@ -9,13 +9,32 @@
 
     <v-row>
       <v-col cols="12" md="9" lg="7" :class="{ 'pb-mobile-cart': isMobile }">
-        <v-card-title>
+        <v-sheet class="page-header d-flex align-center pa-3 pa-sm-4 pa-md-6 mb-3 mb-sm-4 rounded-lg">
-          <span class="headline">Catálogo</span>
+          <v-icon size="28" color="white" class="mr-2 d-sm-none">mdi-store</v-icon>
-        </v-card-title>
+          <v-icon size="36" color="white" class="mr-3 d-none d-sm-inline">mdi-store</v-icon>
+          <div class="d-flex flex-column flex-sm-row align-start align-sm-center w-100 ga-2 ga-sm-4">
+            <div class="flex-shrink-0">
+              <h1 class="text-h6 text-sm-h5 text-md-h4 font-weight-bold text-white mb-0">Catálogo</h1>
+              <p class="text-body-2 text-white text-medium-emphasis mb-0">Explora y agrega productos a tu compra</p>
+            </div>
+            <v-spacer></v-spacer>
+            <v-text-field
+              v-model="searchQuery"
+              prepend-inner-icon="mdi-magnify"
+              label="Buscar producto..."
+              variant="solo-filled"
+              density="compact"
+              clearable
+              hide-details
+              single-line
+              class="search-field"
+            />
+          </div>
+        </v-sheet>
 
         <!-- Controles de paginación superiores -->
         <PaginationControls
-          v-if="items.length > 0"
+          v-if="filteredItems.length > 0"
           :current-page="currentPage"
           :total-pages="totalPages"
           :items-per-page="itemsPerPage"
@@ -52,10 +71,18 @@
         >
           No hay productos disponibles en el catálogo
         </v-alert>
+        <v-alert
+          v-else-if="filteredItems.length === 0"
+          type="warning"
+          class="my-4"
+          variant="tonal"
+        >
+          No se encontraron productos con ese nombre
+        </v-alert>
 
         <!-- Controles de paginación inferiores -->
         <PaginationControls
-          v-if="items.length > 0"
+          v-if="filteredItems.length > 0"
           :current-page="currentPage"
           :total-pages="totalPages"
           :items-per-page="itemsPerPage"
@@ -225,6 +252,7 @@ export default {
     return {
       api: inject("api"),
       items: [],
+      searchQuery: "",
       // Paginación
       currentPage: 1,
       itemsPerPage: 20,
@@ -257,14 +285,22 @@ export default {
     cartCount() {
       return this.cartStore.cartCount;
     },
+    // Búsqueda
+    filteredItems() {
+      if (!this.searchQuery) return this.items;
+      const query = this.searchQuery.toLowerCase();
+      return this.items.filter((item) =>
+        item.name.toLowerCase().includes(query),
+      );
+    },
     // Paginación
     paginatedItems() {
       const start = (this.currentPage - 1) * this.itemsPerPage;
       const end = start + this.itemsPerPage;
-      return this.items.slice(start, end);
+      return this.filteredItems.slice(start, end);
     },
     totalPages() {
-      return Math.ceil(this.items.length / this.itemsPerPage);
+      return Math.ceil(this.filteredItems.length / this.itemsPerPage);
     },
     paginationInfo() {
       const start = (this.currentPage - 1) * this.itemsPerPage + 1;
@@ -275,7 +311,7 @@ export default {
       return {
         start,
         end,
-        total: this.items.length,
+        total: this.filteredItems.length,
       };
     },
     // Computed para total-visible dinámico y responsive (usado por ambos PaginationControls)
@@ -306,6 +342,11 @@ export default {
     this.loadItemsPerPagePreference();
     this.fetchProducts();
   },
+  watch: {
+    searchQuery() {
+      this.currentPage = 1;
+    },
+  },
   methods: {
     fetchProducts() {
       this.api
@@ -446,7 +487,7 @@ export default {
     },
     scrollToTop() {
       this.$nextTick(() => {
-        const catalogHeader = this.$el?.querySelector(".headline");
+        const catalogHeader = this.$el?.querySelector(".page-header");
         if (catalogHeader) {
           catalogHeader.scrollIntoView({
             behavior: "smooth",
@@ -468,59 +509,60 @@ export default {
 </script>
 
 <style scoped>
-.headline {
+.page-header {
-  font-weight: bold;
+  position: sticky;
-  font-size: 1.25rem;
+  top: 80px;
+  z-index: 10;
+  background: linear-gradient(135deg, #1565C0 0%, #0D47A1 100%) !important;
+  color: white !important;
+  overflow: visible;
 }
 
-/* === LISTADO DE PRODUCTOS === */
+@media (max-width: 959px) {
-.catalog-item {
+  .page-header {
-  padding: 0;
+    top: 0;
-  margin-bottom: 12px;
+    border-radius: 0 !important;
-}
-
-.catalog-item:last-child {
-  margin-bottom: 0;
-}
-
-/* Mobile First: Estilos base (< 960px) */
-.cart-sidebar {
-  position: fixed;
-  bottom: 0;
-  left: 0;
-  right: 0;
-  z-index: 1000;
-  transition: all 0.3s ease-in-out;
-}
-
-.cart-backdrop {
-  position: fixed;
-  top: 0;
-  left: 0;
-  right: 0;
-  bottom: 0;
-  background-color: rgba(0, 0, 0, 0.5);
-  z-index: 999;
-  animation: fadeIn 0.3s ease-in-out;
-}
-
-@keyframes fadeIn {
-  from {
-    opacity: 0;
-  }
-  to {
-    opacity: 1;
   }
 }
 
-/* Padding para el contenido del catálogo en mobile */
+@media (max-width: 559px) {
-.pb-mobile-cart {
+  .page-header {
-  padding-bottom: 76px !important; /* 60px sidebar + 16px margen */
+    padding: 12px 16px !important;
+  }
+}
+
+.page-header .search-field {
+  background: rgba(255, 255, 255, 0.15);
+  border-radius: 8px;
+  transition: background 0.2s;
+  width: 100%;
+}
+
+.page-header .search-field:hover,
+.page-header .search-field:focus-within {
+  background: rgba(255, 255, 255, 0.25);
+}
+
+@media (max-width: 559px) {
+  .page-header .search-field :deep(.v-field__input) {
+    font-size: 0.875rem;
+  }
+}
+
+@media (min-width: 560px) {
+  .page-header .search-field {
+    min-width: 260px;
+    max-width: 360px;
+  }
+}
+
+@media (min-width: 960px) {
+  .page-header .search-field {
+    min-width: 320px;
+    max-width: 460px;
+  }
 }
 
-/* Desktop (≥ 960px) - Sidebar sticky con scroll */
-/* Layout: 960-1023px = md breakpoint (75% productos / 25% cart) */
-/* Layout: ≥1024px = lg breakpoint (60% productos / 40% cart) */
 @media (min-width: 960px) {
   .cart-sidebar {
     position: sticky;
@@ -543,18 +585,12 @@ export default {
   }
 }
 
-/* Resolución <560px - Mobile extra small */
 @media (max-width: 559px) {
-  .headline {
-    font-size: 1.1rem;
-  }
-
   .catalog-item {
     margin-bottom: 10px;
   }
 }
 
-/* Resolución 560-959px - Tablet */
 @media (min-width: 560px) and (max-width: 959px) {
   .catalog-item {
     margin-bottom: 14px;