fix(post-form): shorten long uploaded file labels in the form

Telegraph and other hosts can produce very long filenames that overflow the
narrow post form upload row; truncate them more aggressively than post media
links and expose the full name via title tooltip.

src/components/post-form/__tests__/post-form.test.tsx

@@ -643,6 +643,23 @@ describe('PostForm', () => {
     expect(table?.textContent).toContain('file name.jpg');
   });
 
+  it('shortens long pasted file-link filenames next to the upload button', async () => {
+    testState.uploadedFileName = null;
+
+    await renderPostForm('/all');
+    await clickByText(container, 'start_new_thread');
+
+    const table = container.querySelector('table');
+    const textInputs = table?.querySelectorAll<HTMLInputElement>('input[type="text"]') || [];
+    const linkInput = textInputs[2];
+    const longFilename = 'TELEMMGLPICT000378070158_17159651831200_trans_NvBQzQNjv4BqpVlberWd9EgFPZtcLiMQf0Rf_Wk3V23H2268P_XkPxc.jpeg';
+
+    await dispatchInput(linkInput as HTMLInputElement, `https://www.telegraph.co.uk/multimedia/${longFilename}`);
+
+    expect(table?.textContent).toContain('TELEMMGLPICT...P_XkPxc.jpeg');
+    expect(table?.textContent).not.toContain(longFilename);
+  });
+
   it('uses the shared loading ellipsis while a post form upload is running', async () => {
     testState.isUploading = true;
 

src/components/post-form/post-form.tsx

@@ -7,6 +7,7 @@ import getShortAddress from '../../lib/get-short-address';
 import useCommunitiesPagesStore from '@bitsocial/bitsocial-react-hooks/dist/stores/communities-pages';
 import { getDisplayMediaInfoType, getLinkMediaInfo } from '../../lib/utils/media-utils';
 import { getExpiringMediaLinkAlert } from '../../lib/utils/media-link-validation-utils';
+import { truncateWithEllipsisInMiddle } from '../../lib/utils/string-utils';
 import { getPublishURLFilename, isValidPublishURL, isValidURL } from '../../lib/utils/url-utils';
 import { hasModQueueAccessRole } from '../../lib/utils/mod-access';
 import { isAllView, isCatalogView, isModQueueView, isModView, isPostPageView, isSubscriptionsView } from '../../lib/utils/view-utils';
@@ -31,6 +32,13 @@ import capitalize from 'lodash/capitalize';
 import debounce from 'lodash/debounce';
 
 const FILE_LINK_PLACEHOLDER = 'https://website.com/image.jpg';
+const POST_FORM_FILE_DISPLAY_MAX_LENGTH = 28;
+
+const getPostFormFileDisplayLabel = (url: string, uploadedFileName: string | null | undefined, noFileLabel: string): string => {
+  const raw = getPublishURLFilename(url) || uploadedFileName;
+  if (!raw) return noFileLabel;
+  return truncateWithEllipsisInMiddle(raw, POST_FORM_FILE_DISPLAY_MAX_LENGTH);
+};
 
 export const LinkTypePreviewer = ({ link }: { link: string }) => {
   const { t } = useTranslation();
@@ -299,7 +307,9 @@ const PostFormFields = ({
             isUploading={isUploading}
             showUploadControls={showUploadControls}
           />
-          <span>{isUploading ? <LoadingEllipsis string={t('uploading')} /> : getPublishURLFilename(url) || uploadedFileName || t('no_file_chosen')}</span>
+          <span title={getPublishURLFilename(url) || uploadedFileName || undefined}>
+            {isUploading ? <LoadingEllipsis string={t('uploading')} /> : getPostFormFileDisplayLabel(url, uploadedFileName, t('no_file_chosen'))}
+          </span>
         </td>
       </tr>
     )}