feat: add products.list contract

Add products contract with:
- ProductSchema (id, name, description, recurringInterval, prices)
- ProductPriceSchema (amountType, amounts, meterId)
- listProductsContract for products.list endpoint

Author: NatElkins

src/contracts/products.ts

@@ -0,0 +1,37 @@
+import { oc } from "@orpc/contract";
+import { z } from "zod";
+
+export const ProductPriceSchema = z.object({
+  id: z.string(),
+  amountType: z.enum(["FIXED", "CUSTOM", "FREE", "METERED"]),
+  priceAmount: z.number().nullable(),
+  minimumAmount: z.number().nullable(),
+  maximumAmount: z.number().nullable(),
+  presetAmount: z.number().nullable(),
+  unitAmount: z.number().nullable(),
+  capAmount: z.number().nullable(),
+  meterId: z.string().nullable(),
+});
+
+export const ProductSchema = z.object({
+  id: z.string(),
+  name: z.string(),
+  description: z.string().nullable(),
+  recurringInterval: z.enum(["MONTH", "QUARTER", "YEAR"]).nullable(),
+  prices: z.array(ProductPriceSchema),
+});
+
+export const ListProductsOutputSchema = z.object({
+  products: z.array(ProductSchema),
+});
+
+export type Product = z.infer<typeof ProductSchema>;
+export type ProductPrice = z.infer<typeof ProductPriceSchema>;
+
+export const listProductsContract = oc
+  .input(z.object({}).optional())
+  .output(ListProductsOutputSchema);
+
+export const products = {
+  list: listProductsContract,
+};

src/index.ts

@@ -1,5 +1,6 @@
 import { checkout } from "./contracts/checkout";
 import { onboarding } from "./contracts/onboarding";
+import { products } from "./contracts/products";
 
 export type {
 	ConfirmCheckout,
@@ -18,8 +19,10 @@ export type {
 } from "./contracts/onboarding";
 export type { Checkout } from "./schemas/checkout";
 export { CheckoutSchema } from "./schemas/checkout";
+export type { Product, ProductPrice } from "./contracts/products";
+export { ProductSchema, ProductPriceSchema, ListProductsOutputSchema } from "./contracts/products";
 
-export const contract = { checkout, onboarding };
+export const contract = { checkout, onboarding, products };
 
 export type { MetadataValidationError } from "./validation/metadata-validation";
 export {