videobook 0.2.5

Added

• Thirteen fal video endpoints: Kling 4 text, frame, reference and editing;
  HeyGen Video text, image and reference generation; HeyGen Avatar 3/4/5
  stock digital twins, Avatar 4 image animation, and Video Agent v2/v3.
• HeyGen Video text and reference models appear in the ranked pickers.
  Kling 4 appears in the unranked group. Digital twins accept spoken scripts
  with stock avatar and voice defaults; Avatar 4 image animation defaults to Ivy.

Changed

• Upgrade all Apicity packages to 0.17.1 and refresh generated model documentation.