[ptgrogan]

• Add compute_local_incidence_angle and the preprocessing methods compute_terrain_slope_aspect and add_local_incidence_angles, which sample a DEM's slope and aspect (bilinear, across tile seams) at the targets of ground pixels or observations (closes Add surface incidence angle option to ground track pixels #128).
• Accept a GeoDataFrame or GeoSeries of points in collect_observations.
• Fix compute_along_track_field_of_view to subtend the ground track's advance from the satellite's height above the WGS 84 ellipsoid, so that consecutive footprints tile without gaps at low latitudes (up to 83 m per scan for NOAA-20 VIIRS before).
• Add docs/validation/summary.rst, summarizing the validation results by capability, with modeling guidance and the limits of the models.
• Add a detailed VIIRS model section to the CollectOrbitGroundTrack example, and rerun all example notebooks and the validation notebooks that tailor along-track fields of view, updating their cited results and fixing pandas 3 and shapely deprecation issues in them.
• Replace the deprecated shapely.ops.transform, move joblib to the examples extra, and document running tests with pytest.