[MCantuncer]

Can asked for small but effective thumbnails in Spotlight, not a wide lead photo.

• Every Spotlight photo is now a square thumbnail. On wide screens it's 88px beside the text, next to the kind badge. On phones it's 64px and takes the badge's place, so the text keeps its width.
• The 16:9 lead photo is gone.
• The connector line between items stays centred on a thumbnail.
• and-finally.md records the change.

pnpm check passes. I checked it at 390px with placeholder photos. This touches only AndFinally.astro and the decision doc, so it doesn't conflict with #83 or #84.