The image routes call VideoGenerator.generate with a GenerationRequest
instead of passing flat generate_video keywords. The flat projection
_build_generation_kwargs in video_api.py had no runtime caller, so it is
removed, and its tests exercise build_generation_request instead.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012M91wnVFmPEvJ9h39r5BH7