Publication teaser images

Drop a teaser figure here and reference it from _data/publications.yml:

- key: exfiqa
  teaser: exfiqa.jpg

Guidelines:

• Aspect ratio 16:10 (e.g. 1280×800). Anything else is centre-cropped.
• JPG for photos/figures, PNG for diagrams with flat colour.
• Keep each file under ~400 KB. These load on the homepage.
• Expected filenames (matching the entries already in publications.yml): exfiqa.jpg, attnfiqa.jpg, vitntfiqa.jpg, foundpad.jpg, tpo.jpg, expl-fr.jpg, prefiqs.jpg, dcmorph.jpg, madation.jpg

Any entry without a teaser renders a typographic placeholder card instead, so missing images never break the layout.