Transport row is now the five-button audiobook shape the user asked
for: previous-chapter · circular-skip-back (seconds displayed inside
the ring) · play/pause · circular-skip-forward · next-chapter — the
ring arrows are stroke SVGs (rotate-ccw/rotate-cw) with the number as
an overlay so it stays upright and follows the skip setting.
Settings strip collapses to four controls: Skip dropdown, Speed
dropdown, Bookmark (capture popover unchanged), Volume. Volume opens
a panel with a vertical dragger (writing-mode:rtl slider) and a
mute/unmute button; the strip icon is dynamic — 1–3 arcs by level (low
<34%, mid <67%, high) and crossed when muted or zero. Volume/mute
persist in localStorage and restore with the element; unmute floors
zero-volume to 50% so unmuting is audible.
Verified on-device: dropdowns open upward with current value
highlighted, mute flips both icons to the crossed state, slider
drag changes arc count, chapter buttons jump (pill → 15/34) and the
caption tracks the drawer's chapter labels.