The circular button covered artwork exactly while reading. The tab keeps the
drag-and-snap behaviour and the mangabm:fabpos key; only its box changes. The
dwell countdown becomes a bottom-up fill of the tab, since a sliver has no room
for a ring.
Also fixes a latent bug the new shape exposes: placeFab and makeDraggable used
offsetWidth for the vertical clamp too. Invisible on a 52px circle, off by 37px
on a 7x44 tab.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
sulthan
04359ea034