Player controls — near end
position=0.94. Confirms the handle sits inside the track at the
right edge — no overflow past the rounded end-cap, no clipping. The
margin-left: -6px on .player-scrub-handle exactly cancels the half-width
so the handle's center aligns with the position percentage.
This story exists specifically to lock that boundary. Without it, a careless tweak to handle dimensions could push the dot off the end of the track and the SSR snapshot wouldn't catch the visual regression — only this kind of "edge case" story does.