click or tap a person's avatar to enlarge it 5x

- tap/click once to enable `zoom-in` icon overlay - tap/click again to lightbox it - build this feature into the avatar component as a prop, nullable, and off by default - then enable the prop on person and horse detail pages only for now

- tap/click once to enable `zoom-in` icon overlay - tap/click again to lightbox it - build this feature into the avatar component as a prop, nullable, and off by default - then enable the prop on person and horse detail pages only for now