docs: add JSDoc headers to all externally exported store functions

src/store/tax/create.js

@@ -1,6 +1,17 @@
 import { CREATE } from '../../sql/tax.js';
 import request from '../request.js';
 
+/**
+ * Creates a new tax rate.
+ *
+ * @param {object} pool - The mssql connection pool.
+ * @returns {Function} An async function that creates a tax rate.
+ *
+ * @example
+ * const fn = create(pool);
+ * const id = await fn(19);
+ * // => 1
+ */
 export default function create(pool) {
   return async (rate, tx) => {
     const result = await request(pool, tx)

src/store/tax/ensure.js

@@ -1,6 +1,17 @@
 import getByRate from './getByRate.js';
 import create from './create.js';
 
+/**
+ * Returns the id of a tax rate, creating it if it does not exist.
+ *
+ * @param {object} pool - The mssql connection pool.
+ * @returns {Function} An async function that ensures a tax rate exists.
+ *
+ * @example
+ * const fn = ensure(pool);
+ * const id = await fn(19);
+ * // => 1
+ */
 export default function ensure(pool) {
   const get = getByRate(pool);
   const add = create(pool);

src/store/tax/getByRate.js

@@ -1,6 +1,17 @@
 import { GET_BY_RATE } from '../../sql/tax.js';
 import request from '../request.js';
 
+/**
+ * Returns a tax row by its rate.
+ *
+ * @param {object} pool - The mssql connection pool.
+ * @returns {Function} An async function that fetches a tax rate.
+ *
+ * @example
+ * const fn = getByRate(pool);
+ * const tax = await fn(19);
+ * // => { id, rate }
+ */
 export default function getByRate(pool) {
   return async (rate, tx) => {
     const result = await request(pool, tx)

src/store/tax/list.js

@@ -1,5 +1,16 @@
 import { LIST } from '../../sql/tax.js';
 
+/**
+ * Lists all tax rates.
+ *
+ * @param {object} pool - The mssql connection pool.
+ * @returns {Function} An async function that lists tax rates.
+ *
+ * @example
+ * const fn = list(pool);
+ * const taxes = await fn();
+ * // => [{ id, rate }]
+ */
 export default function list(pool) {
   return async () => {
     const result = await pool.request().query(LIST);