feat(saleor): Phase 1 - GraphQL Client Setup

- Add Apollo Client for Saleor GraphQL API
- Create GraphQL fragments (Product, Variant, Checkout)
- Create GraphQL queries (Products, Checkout)
- Create GraphQL mutations (Checkout operations)
- Add TypeScript types for Saleor entities
- Add product helper functions
- Install @apollo/client and graphql dependencies

Part of WordPress/WooCommerce → Saleor migration

src/types/saleor.ts

@@ -0,0 +1,191 @@
+// Saleor GraphQL Types
+
+export interface Money {
+  amount: number;
+  currency: string;
+}
+
+export interface Price {
+  gross: Money;
+  net?: Money;
+}
+
+export interface DiscountedPrice {
+  gross: Money;
+}
+
+export interface ProductMedia {
+  id: string;
+  url: string;
+  alt: string;
+  type: string;
+}
+
+export interface ProductAttributeValue {
+  name: string;
+  slug: string;
+}
+
+export interface ProductAttribute {
+  attribute: {
+    name: string;
+    slug: string;
+  };
+  values: ProductAttributeValue[];
+}
+
+export interface ProductVariantPricing {
+  price: Price;
+  onSale: boolean;
+  discount?: DiscountedPrice;
+}
+
+export interface ProductVariant {
+  id: string;
+  name: string;
+  sku: string;
+  quantityAvailable: number;
+  weight?: {
+    value: number;
+    unit: string;
+  };
+  media?: ProductMedia[];
+  pricing?: ProductVariantPricing;
+  attributes?: ProductAttribute[];
+}
+
+export interface ProductTranslation {
+  id: string;
+  name: string;
+  slug: string;
+  description: string;
+  seoTitle?: string;
+  seoDescription?: string;
+}
+
+export interface Product {
+  id: string;
+  name: string;
+  slug: string;
+  description: string;
+  seoTitle?: string;
+  seoDescription?: string;
+  translation?: ProductTranslation;
+  variants: ProductVariant[];
+  media: ProductMedia[];
+  category?: {
+    id: string;
+    name: string;
+    slug: string;
+  };
+  metadata?: {
+    key: string;
+    value: string;
+  }[];
+}
+
+export interface ProductEdge {
+  node: Product;
+}
+
+export interface ProductList {
+  edges: ProductEdge[];
+  pageInfo: {
+    hasNextPage: boolean;
+    endCursor?: string;
+  };
+}
+
+// Checkout Types
+
+export interface Address {
+  id?: string;
+  firstName: string;
+  lastName: string;
+  companyName?: string;
+  streetAddress1: string;
+  streetAddress2?: string;
+  city: string;
+  postalCode: string;
+  country: {
+    code: string;
+    country: string;
+  };
+  countryArea?: string;
+  phone?: string;
+}
+
+export interface CheckoutLine {
+  id: string;
+  quantity: number;
+  totalPrice: Price;
+  variant: ProductVariant & {
+    product: {
+      id: string;
+      name: string;
+      slug: string;
+      media: ProductMedia[];
+    };
+  };
+}
+
+export interface ShippingMethod {
+  id: string;
+  name: string;
+  price: Money;
+}
+
+export interface PaymentGateway {
+  id: string;
+  name: string;
+}
+
+export interface Checkout {
+  id: string;
+  token: string;
+  email?: string;
+  isShippingRequired: boolean;
+  lines: CheckoutLine[];
+  shippingPrice: Price;
+  subtotalPrice: Price;
+  totalPrice: Price;
+  shippingAddress?: Address;
+  billingAddress?: Address;
+  shippingMethods: ShippingMethod[];
+  availablePaymentGateways: PaymentGateway[];
+  note?: string;
+}
+
+// Order Types
+
+export interface Order {
+  id: string;
+  number: string;
+  status: string;
+  created: string;
+  total: Price;
+}
+
+// API Response Types
+
+export interface CheckoutCreateResponse {
+  checkoutCreate: {
+    checkout?: Checkout;
+    errors: Array<{
+      field: string;
+      message: string;
+      code: string;
+    }>;
+  };
+}
+
+export interface CheckoutCompleteResponse {
+  checkoutComplete: {
+    order?: Order;
+    errors: Array<{
+      field: string;
+      message: string;
+      code: string;
+    }>;
+  };
+}