Drop a cover photo here for each built-in reading plan, named exactly:

  bible-year.jpg      Whole Bible in a Year
  bible-90.jpg        Whole Bible in 90 Days
  nt-90.jpg           New Testament in 90 Days
  nt-30.jpg           New Testament in 30 Days
  gospels-30.jpg      The Gospels in 30 Days
  psalms-30.jpg       Psalms in 30 Days
  proverbs-31.jpg     Proverbs in 31 Days
  pentateuch-60.jpg   The Pentateuch in 60 Days
  wisdom-40.jpg       Wisdom Literature in 40 Days

Landscape orientation, ~1200px wide, works best (cards crop to a 16:9 box).
Any plan without a matching file just shows its colorful gradient + icon —
nothing breaks if some are missing.

See src/utils/readingPlans.js -> PIXABAY_SEARCH_LINKS for a Pixabay search
link per plan to help pick one.
