feat(manifest): add externalNumber reference to quote/order/delivery

- Add `external_number NVARCHAR(100)` column to the `manifest` table.
- Thread `externalNumber` through manifestDoc and delivery SQL (list,
  header, create, update).
- Include `externalNumber` in shapeSummary and quote/order/delivery
  create/update/list/getById handlers (optional, clearable on update).
- Update README type definitions and regenerate API/schema docs.

src/store/order/list.js

@@ -9,11 +9,11 @@ export default function list(pool) {
    * Lists the orders of the user's selected company.
    *
    * @param {number} googleAuthId - The id of the Google auth user.
-   * @returns {Promise<Array<{id: number, number: string, type: string, entityId: number|null, date: string}>>} The orders.
+   * @returns {Promise<Array<{id: number, number: string, type: string, entityId: number|null, externalNumber: string|null, date: string}>>} The orders.
    *
    * @example
    * const orders = await store.order.list(42);
-   * // => [{ id, number, type, entityId, date }]
+   * // => [{ id, number, type, entityId, externalNumber, date }]
    */
   return async (googleAuthId) => {
     const { companyId } = await access(googleAuthId);