align with hs2p

[clemsgrs]

Summary

• align slide2vec with hs2p 3.3.0 and 4.0.0
• keep the bundled preprocessing schema in sync with hs2p's AtlasPatch-capable sam2 segmentation path
• update slide2vec for hs2p's unified tiling/sampling contract, including the explicit preview toggles and annotation process-list column

Why

hs2p 3.3.0 introduced the segmentation.method / sam2_* schema, and hs2p 4.0.0 unified tiling and sampling around a stricter process-list contract plus explicit preview toggles. Without this update, slide2vec would keep shipping config/docs/tests that no longer match the upstream dependency.

What changed

• bumped the hs2p dependency floor to 3.3.0 and included the sam2 extra in the packaged install
• updated slide2vec/configs/default.yaml to use the new preview booleans and tissue contour styling fields expected by hs2p 4.0.0
• preserved hs2p's new annotation column when slide2vec reloads and rewrites process lists
• refreshed the Python API and CLI docs to describe sam2, AtlasPatch-backed segmentation, and the explicit preview toggles
• updated regression coverage and the stored metadata fixtures to match the new hs2p schema