UI fixes and polish since v0.6.0.
Changes
- Dark-mode legibility: the active Step/Turn toggle button now uses the harness's primary-button pairing (
button-primary-fill+label-primary-foreground) — dark themes resolve the brand color to near-white, which made the old white-on-white text invisible. - Bidirectional composition hover: hovering a legend chip now also lights the matching segment AND shows the tooltip (derived from the shared hover key, centered on the segment); hovering a segment still does both.
- Granularity re-anchor: switching step ↔ turn scrolls the history back to the newest bars (the narrow turn chart had left a stale left-edge position).
- Regression guard: a real-React + jsdom render smoke covers the step → turn → step toggle with a 460-request snapshot.