Add AI store assistant with catalogue tool calls

- /api/chat streams via AI SDK v7 through OpenRouter (OPENROUTER_API_KEY),
  with a store-specific system prompt and five read-only tools:
  searchCatalogue, getProductDetails, listCollections,
  getCollectionProducts, browseProducts
- Sidebar assistant on the right that opens from a launcher and expands,
  built on ai-elements (conversation, message, prompt-input, tool) with
  shimmer on in-flight tool calls
- Extract services/shopify/catalog.ts so the Storefront fetchers have no
  React imports and can run in a Route Handler; the client hooks now
  re-export from it
- ai-elements pulled in the canonical shadcn primitives, replacing the
  hand-rolled command/dialog/button variants; search dialog moved to the
  cmdk-based Command and CommandDialog forwards shouldFilter
- Pin shiki to ^3.19.0 to match streamdown and drop the duplicate copy
- Add .env.example documenting the required env vars

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016jWbNNJLksC1QG8z8845FX

hooks/use-shopify-search.ts

@@ -1,120 +1,10 @@
-'use client';
-
-import { shopifyFetch } from '@/services/shopify/client';
-import {
-  SEARCH_PRODUCTS_QUERY,
-  SEARCH_SUGGESTIONS_QUERY,
-} from '@/graphql/search';
-import type { Product } from '@/hooks/use-shopify-products';
-
-export type SearchSortKey = 'RELEVANCE' | 'PRICE';
-
-export interface SearchFilterValue {
-  id: string;
-  label: string;
-  count: number;
-  /** JSON string accepted back as a `ProductFilter` input. */
-  input: string;
-}
-
-export interface SearchFilter {
-  id: string;
-  label: string;
-  type: 'LIST' | 'PRICE_RANGE' | 'BOOLEAN';
-  values: SearchFilterValue[];
-}
-
-export interface SearchProductsResult {
-  products: Product[];
-  totalCount: number;
-  filters: SearchFilter[];
-  hasNextPage: boolean;
-  endCursor: string | null;
-}
-
-export interface SearchSuggestion {
-  id: string;
-  title: string;
-  handle: string;
-  featuredImage?: {
-    url: string;
-    altText?: string;
-  } | null;
-  priceRange: {
-    minVariantPrice: {
-      amount: string;
-      currencyCode: string;
-    };
-  };
-}
-
-interface SearchProductsOptions {
-  query: string;
-  first?: number;
-  after?: string | null;
-  sortKey?: SearchSortKey;
-  reverse?: boolean;
-  /** Raw `input` strings from the facets, parsed back into filter objects. */
-  filterInputs?: string[];
-}
-
-function parseFilterInputs(inputs: string[]): unknown[] {
-  return inputs.flatMap((input) => {
-    try {
-      return [JSON.parse(input)];
-    } catch {
-      console.warn('Ignoring malformed product filter input:', input);
-      return [];
-    }
-  });
-}
-
-export async function searchProducts({
-  query,
-  first = 24,
-  after = null,
-  sortKey = 'RELEVANCE',
-  reverse = false,
-  filterInputs = [],
-}: SearchProductsOptions): Promise<SearchProductsResult> {
-  const response = await shopifyFetch({
-    query: SEARCH_PRODUCTS_QUERY,
-    variables: {
-      query,
-      first,
-      after,
-      sortKey,
-      reverse,
-      productFilters: filterInputs.length
-        ? parseFilterInputs(filterInputs)
-        : null,
-    },
-  });
-
-  const search = response.data.search;
-
-  return {
-    products: search.edges.map((edge: { node: Product }) => edge.node),
-    totalCount: search.totalCount ?? 0,
-    filters: search.productFilters ?? [],
-    hasNextPage: Boolean(search.pageInfo?.hasNextPage),
-    endCursor: search.pageInfo?.endCursor ?? null,
-  };
-}
-
-export async function searchSuggestions(
-  query: string,
-  first = 3
-): Promise<{ products: SearchSuggestion[]; totalCount: number }> {
-  const response = await shopifyFetch({
-    query: SEARCH_SUGGESTIONS_QUERY,
-    variables: { query, first },
-  });
-
-  const search = response.data.search;
-
-  return {
-    products: search.edges.map((edge: { node: SearchSuggestion }) => edge.node),
-    totalCount: search.totalCount ?? 0,
-  };
-}
+// Re-exported from the server-safe catalogue module so both client components
+// and Route Handlers can search the storefront.
+export { searchProducts, searchSuggestions } from '@/services/shopify/catalog';
+export type {
+  SearchSortKey,
+  SearchFilter,
+  SearchFilterValue,
+  SearchProductsResult,
+  SearchSuggestion,
+} from '@/services/shopify/catalog';