test: add integration test for TIFF image loading pipeline

Adds a Playwright test that loads a minimal DOCX containing a TIFF image
and verifies the full pipeline: DocxZipper → convertTiffToPng → rendered PNG.

Author: gpardhivvarma

tests/behavior/tests/importing/fixtures/tiff-image.docx

@@ -0,0 +1,28 @@
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
+import { test, expect } from '../../fixtures/superdoc.js';
+import { assertDocumentApiReady, getDocumentText } from '../../helpers/document-api.js';
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
+const DOC_PATH = path.resolve(__dirname, 'fixtures/tiff-image.docx');
+
+test.use({ config: { toolbar: 'full', comments: 'off' } });
+
+test('loads DOCX with TIFF image and renders it as PNG', async ({ superdoc }) => {
+  await superdoc.loadDocument(DOC_PATH);
+  await superdoc.waitForStable();
+  await assertDocumentApiReady(superdoc.page);
+
+  // Document text is present
+  const text = await getDocumentText(superdoc.page);
+  expect(text).toContain('TIFF test document');
+
+  // Editor is functional — pages and lines rendered
+  await expect(superdoc.page.locator('.superdoc-page').first()).toBeVisible();
+  await expect(superdoc.page.locator('.superdoc-line').first()).toBeVisible();
+
+  // The TIFF was converted to PNG — the rendered <img> should have a PNG data URI
+  const imgSrc = await superdoc.page.locator('img').first().getAttribute('src');
+  expect(imgSrc).toBeTruthy();
+  expect(imgSrc).toContain('data:image/png');
+});