Phone preview with the video's own thumbnail. site-free-tool @dc908e5 (PREVIEW ONLY, not deployed)

Layout fixture: the made-up coaching text from earlier screens, with the Ep.39 video id, so the thumbnail is the real one YouTube serves for Ep.39. Rendered from the committed dist under the real /tools/* CSP. No console or CSP errors, and no sideways scroll at 390.

• Only YouTube's 16:9 sizes are used (320x180, and 1280x720 when the video has one), shown exactly as served: no crop, cover or overlay. Phones with sharp screens get the 1280 image, others the 320.
• The thumbnail links to the video on YouTube, and the note under it names YouTube as the source (Developer Policies III.F.2.a).
• No thumbnail, a failed load, or a removed video (YouTube then sends a small 4:3 stand-in): the plain panel and the old note come back.