- Switch default Gemini video model to veo-3.1-lite-generate-preview (50% cheaper)
- Add image_path tool param for image-to-video generation (Gemini Veo only)
- Add resolution and generate_audio as per-provider chain params in UI
- Support dual response formats (Veo 3.1 generatedVideos + Veo 3.0 generatedSamples)
- Gracefully skip image-to-video on providers that don't support it (MiniMax, chat)
- Split create_video into per-provider files (gemini, minimax, chat) for maintainability
