This version presents a more complete version of tangent lines.

It builds a line by plotting the tangent points to the siblings through a psuedo center (a "pin" projected out from each point along its bisector direction). This ensures the arc is drawn through the center rather than arcing around the outside, and - importantly - keeps the belt's tangent side selection changing continuously as a point is dragged, rather than snapping between the two inbound tangent sides whenever a point crosses the center-line of its neighbours.

The pin is projected a distance scaled by how sharp the local bend actually is (bendMagnitude, 0 for a point sitting in a near straight line between its neighbours, up to 2 for a sharp reversal). Projecting a full radius regardless of bend sharpness caused the pin offset and the tangent formula's own radius offset to compound on gentle/near-straight bends, landing the plotted meeting tips up to a full diameter away from the real point.

The arc sweep direction (resolveArcDirection) still needs a guard for the near-collinear case: when a point sits (almost) in a straight line between its neighbours, the two touch points collapse onto nearly the same spot, so floating point jitter alone shouldn't be allowed to pick the reflex/near-full loop over the intended near-zero arc.