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/quote/create.js

@@ -17,13 +17,14 @@ export default function create(pool) {
    * @param {string} body.number - The quote number.
    * @param {string} body.date - The quote date.
    * @param {number} [body.entityId] - The id of the customer entity.
+   * @param {string} [body.externalNumber] - An external (customer) reference number.
    * @param {Array<object>} [body.lines] - The quote lines.
-   * @returns {Promise<{id: number, number: string, type: string, entityId: number|null, date: string, lines: Array<object>}>} The created quote.
+   * @returns {Promise<{id: number, number: string, type: string, entityId: number|null, externalNumber: string|null, date: string, lines: Array<object>}>} The created quote.
    * @throws {Error} If the quote is invalid.
    *
    * @example
    * const quote = await store.quote.create(42, { number: 'A-2026-001', date: '2026-09-01', entityId: 12, lines: [...] });
-   * // => { id, number, type, entityId, date, lines: [...] }
+   * // => { id, number, type, entityId, externalNumber, date, lines: [...] }
    */
   return async (googleAuthId, body = {}) => {
     const number = body.number?.trim?.() ? body.number.trim() : null;
@@ -31,6 +32,9 @@ export default function create(pool) {
     if (!number || !date) {
       throw new Error('Invalid quote');
     }
+    const externalNumber = body.externalNumber?.trim?.()
+      ? body.externalNumber.trim()
+      : null;
 
     const lines = normalizeLines(body.lines ?? []);
     const { companyId, rootCategoryId } = await access(googleAuthId);
@@ -51,6 +55,7 @@ export default function create(pool) {
         .input('number', number)
         .input('type', QUOTE_TYPE)
         .input('entityId', entityId)
+        .input('externalNumber', externalNumber)
         .input('date', date)
         .query(CREATE_MANIFEST);