Fall through to the post page when a reel embeds only its cover frame

The captioned embed stopped shipping a reel's video_url and never draws a
logged-out <video>, so both the payload and the DOM hand back the cover
frame alone. Because that still counts as media, the post-page fallback
never fired and a reel resolved to a still image.

Trigger the fallback when the URL is a reel (or the payload declared a
video) but no video was found, so it reaches the post page, whose payload
still carries the progressive file in video_versions. The embed's
caption, handle and avatar are carried forward, since the post-page
payload does not include the owner.

Co-authored-by: anthropic/claude-opus-4-8

test/instagram.test.ts

@@ -1,6 +1,7 @@
 import assert from 'node:assert/strict';
 import { test } from 'node:test';
 import { fromGraph } from '../src/platforms/instagram.ts';
+import { findMetaMedia, mediaFromMetaNode } from '../src/platforms/meta-media.ts';
 import { fixture } from './helpers.ts';
 
 test('a carousel becomes one media entry per child, in order', () => {
@@ -26,6 +27,24 @@ test('a reel becomes a progressive video with its cover frame as the poster', ()
   assert.ok(item?.width && item.height, 'expected dimensions for the aspect ratio');
 });
 
+test('a reel whose embed only ships a cover frame still finds its video on the post page', () => {
+  // The captioned embed stopped shipping a reel's `video_url` and never draws
+  // a logged-out `<video>`, so both payload and DOM hand back the poster only.
+  // The post page still carries the progressive file in `video_versions`
+  // (the meta-media schema), which is where the adapter now falls through to.
+  const node = findMetaMedia(fixture('instagram/reel-video-versions.json'));
+  assert.ok(node, 'expected to find the media node in the post payload');
+  const media = mediaFromMetaNode(node!, 'https://www.instagram.com/');
+  assert.equal(media.length, 1);
+  const [item] = media;
+  assert.equal(item?.kind, 'video', 'a reel is a video, not its cover frame');
+  assert.match(item?.url ?? '', /^https:\/\/.*\.mp4/);
+  assert.ok(!item?.url.includes('.m3u8'), 'the native player needs a real file, not HLS');
+  // The cover frame becomes the poster, not the media itself.
+  assert.ok(item?.kind === 'video' && item.poster?.url.includes('t51.82787-15'), 'expected the cover frame as poster');
+  assert.ok(item?.width === 720 && item.height === 1280, 'expected dimensions for the aspect ratio');
+});
+
 test('captions keep their line breaks', () => {
   const scraped = fromGraph(fixture('instagram/carousel.json'));
   assert.ok(scraped.text?.includes('\n'), 'expected the caption to keep paragraph breaks');