`habit.habitat_model`: fit and assign habitats

Built-in habitat model fitters and their registry.

User guide: Habitat domain API · Habitat Guide Fitting a cohort habitat model. Component names: Habitat Spec component catalog.

Classes

`HabitatModelFitter`	Fit the population-level habitat definition.
`KMeansHabitatModelFitter`	Learn population habitats by k-means over pooled supervoxel features.
`GmmHabitatModelFitter`	Learn population habitats by a Gaussian mixture over pooled features.
`HabitatModelFitterRegistry`	Name-to-implementation registry for cohort-level habitat model fitters.
`HabitatAssigner`	Assign habitat labels to one subject using a fitted model.
`NearestCentroidAssigner`	Assign each supervoxel to the habitat of its nearest centroid.
`HabitatAssignerRegistry`	Name-to-implementation registry for per-subject habitat assigners.
`ConnectedComponentPostprocess`	Clean tiny connected components inside an ROI label map.

Build a postprocess operator from a Spec, or None when unset.