v0.1.16

What's Changed

• Added PlottableData.hexbin(...) and fixed hexbin distortion/aspect behavior on non-square axes by using axis-range ratio adjustments.
• Enhanced scatter plotting with a fitted trend line option fit.
• Refined histogram fit-curve rendering by aligning fit-line color with histogram bars and darkening the fit curve for clearer contrast.
• Completed plotting style API naming cleanup: fmt naming was finalized to linestyle or marker.

Full Changelog: v0.1.15...v0.1.16