Import: downloadable Word template for the session list

A blank three-column session list (Session #, Title, Passage) with instructions and
example rows, built in the browser on demand. A test imports the generated file back
through the real importer.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

src/utils/importTemplate.test.js

@@ -0,0 +1,37 @@
+import { test, expect, vi } from 'vitest';
+import { Packer } from 'docx';
+import { buildImportTemplateDocument, TEMPLATE_ROWS } from './importTemplate.js';
+import { parseEpisodeListDocx, parseEpisodePassage } from './importParsers.js';
+
+// Real uploads run in the browser, where mammoth takes an ArrayBuffer; its Node build takes a
+// Buffer. Adapt so the same importer code can run here.
+vi.mock('mammoth', async () => {
+  const real = await vi.importActual('mammoth');
+  const convertToHtml = ({ arrayBuffer }) => real.convertToHtml({ buffer: Buffer.from(arrayBuffer) });
+  return { default: { convertToHtml } };
+});
+
+// Runs the generated file through the same importer real uploads go through.
+async function importTemplate() {
+  const buf = await Packer.toBuffer(buildImportTemplateDocument());
+  const arrayBuffer = buf.buffer.slice(buf.byteOffset, buf.byteOffset + buf.byteLength);
+  return parseEpisodeListDocx({ arrayBuffer: async () => arrayBuffer });
+}
+
+test('the template imports back as exactly its example rows (header and instructions are ignored)', async () => {
+  const sessions = await importTemplate();
+  expect(sessions.map((s) => [s.episodeNumber, s.title, s.passage])).toEqual(TEMPLATE_ROWS);
+});
+
+test('every example passage is one the importer understands', async () => {
+  const sessions = await importTemplate();
+  const parsed = sessions.map((s) => parseEpisodePassage(s.passage));
+  expect(parsed).not.toContain('invalid');
+  expect(parsed[0]).toEqual({ startChapter: 1, startVerse: 1, endChapter: 1, endVerse: 4 });
+  expect(parsed[3]).toBeNull(); // the "—" row has no passage
+  expect(parsed[5]).toEqual({ startChapter: 2, startVerse: 11, endChapter: 3, endVerse: 2 }); // crosses a chapter
+});
+
+test('the sessions are numbered in order with no gaps', () => {
+  expect(TEMPLATE_ROWS.map((r) => r[0])).toEqual(['1', '2', '3', '4', '5', '6']);
+});