docs: add JSDoc headers to all externally exported store functions

src/store/lang/create.js

@@ -1,6 +1,17 @@
 import { CREATE } from '../../sql/language.js';
 import request from '../request.js';
 
+/**
+ * Creates a new language by its ISO 639 code.
+ *
+ * @param {object} pool - The mssql connection pool.
+ * @returns {Function} An async function that creates a language.
+ *
+ * @example
+ * const fn = create(pool);
+ * const id = await fn('de');
+ * // => 1
+ */
 export default function create(pool) {
   return async (iso639, tx) => {
     const result = await request(pool, tx)

src/store/lang/delete.js

@@ -1,5 +1,15 @@
 import { DELETE } from '../../sql/language.js';
 
+/**
+ * Deletes a language by its id.
+ *
+ * @param {object} pool - The mssql connection pool.
+ * @returns {Function} An async function that deletes a language.
+ *
+ * @example
+ * const fn = del(pool);
+ * await fn(1);
+ */
 export default function del(pool) {
   return async (id) => {
     await pool

src/store/lang/ensure.js

@@ -1,6 +1,17 @@
 import getByIso639 from './getByIso639.js';
 import create from './create.js';
 
+/**
+ * Returns the id of a language by ISO code, creating it if it does not exist.
+ *
+ * @param {object} pool - The mssql connection pool.
+ * @returns {Function} An async function that ensures a language exists.
+ *
+ * @example
+ * const fn = ensure(pool);
+ * const id = await fn('de');
+ * // => 1
+ */
 export default function ensure(pool) {
   const get = getByIso639(pool);
   const add = create(pool);

src/store/lang/getByIso639.js

@@ -1,6 +1,17 @@
 import { GET_BY_ISO639 } from '../../sql/language.js';
 import request from '../request.js';
 
+/**
+ * Returns a language row by its ISO 639 code.
+ *
+ * @param {object} pool - The mssql connection pool.
+ * @returns {Function} An async function that fetches a language by ISO code.
+ *
+ * @example
+ * const fn = getByIso639(pool);
+ * const lang = await fn('de');
+ * // => { id, iso639 }
+ */
 export default function getByIso639(pool) {
   return async (iso639, tx) => {
     const result = await request(pool, tx)

src/store/lang/list.js

@@ -1,5 +1,16 @@
 import { LIST } from '../../sql/language.js';
 
+/**
+ * Lists all languages.
+ *
+ * @param {object} pool - The mssql connection pool.
+ * @returns {Function} An async function that lists languages.
+ *
+ * @example
+ * const fn = list(pool);
+ * const languages = await fn();
+ * // => [{ id, iso639 }]
+ */
 export default function list(pool) {
   return async () => {
     const result = await pool.request().query(LIST);