v2.0.0

Added

• AlphaGenome 2 model API (alphagenome.models.v2), supporting
  reference-condition and single-cell expression-conditioned predictions,
  variant and interval scoring, cell embeddings, and input gradients.
• GeneExpressionData container for gene-level expression predictions.
• Enhancer-to-gene scoring and calling utilities
  (alphagenome.interpretation.enhancer_scoring).
• GeneExpression, OverlaidGeneExpression, and EnhancerArcs plot
  components.
• filter_to_observed helper on TrackData and JunctionData.
• Tutorials, vignettes, and user guides for AlphaGenome 2.

Removed

• Deprecated alphagenome.models.* v1 aliases; import from
  alphagenome.models.v1 instead.