* feat(studio): timeline clips take the designed material
Picture clips use an 8px radius and audio clips a 21px pill.
Clips sit one step above the lane. The label is a chip that
drops under 60px. Selection keeps the inset outline plus a
1px inner highlight. Hover background is the only transition.
* style(studio): format timeline clip shadow
* fix(studio): restore handle-bar transition and de-pin box-shadow test