fix: correct mobile connector/node geometry accounting for ol padding
The spine's absolute position is measured from the <ol> border edge, but
abs-positioned children of .timeline-item use the item's padding box as
reference. With px-4 (16px) on .timeline and margin-left: 30px on the item,
the item left sits at 46px from the <ol> border. Spine right = 22px, so
relative to item = -24px. Fixed connector to left:-24px/width:24px and
node to left:-30px so both touch the spine correctly on mobile.
Co-Authored-By: Claude Haiku 4.5 <redacted>
