Slate v2 Location Utility Surface Recovery

Goal

Recover the missing Path, Point, and Range helper breadth that serious headless Slate callers still expect.

Completed

• restored the missing Path.* relationship helpers:
  • endsAfter
  • endsAt
  • endsBefore
  • isAfter
  • isChild
  • isCommon
  • isDescendant
  • isParent
  • isSibling
  • relative
  • operationCanTransformPath
• restored Path.transform(...)
• restored Point.transform(...)
• restored the missing Range.* helpers:
  • equals
  • surrounds
  • intersection
  • isBackward
  • isExpanded
  • isForward
  • points
  • transform
• widened snapshot-contract.ts to prove the recovered location utility seam

Verification

• yarn test:custom
• yarn lint:typescript