Drawing only the selected tab's family hid every other connection until you
clicked into one. All families are drawn again (still as routed trees); the
selected tab's families (what it spawned, and the family it was spawned into)
get .lineage-family--focus: 2.5px instead of 1.5px, full opacity instead of
0.75, a larger end dot, and drawn last so nothing covers them.
Lanes follow strip order (cycling through CodemanLineage.MAX_LANES, 3), never
the selection, so a family's lines never move when you click a tab.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>