Release 0.6.3

Version 0.6.3 (2025-10-11):

https://pypi.org/project/sfs/0.6.3/

• Drop support for numpy 1.x
• Register the colormaps cividis, inferno, magma, plasma,
  viridis, RdBu, coolwarm and their reversed versions as *_clip,
  e.g. viridis_r_clip, with a dedicated max/min value color clipping
• Use viridis_clip colormap as default for sfs.plot2d.level()
• Use coolwarm_clip colormap as default for sfs.plot2d.amplitude()
• Level contour plot via sfs.plot2d.level_contour()
• Add Jupyter notebook for
  2.5D WFS referencing scheme (in examples/wfs-referencing.ipynb) examples