- Introduced `/openai/v1/videos` endpoint to support OpenAI-specific video generation.
- Added error normalization and handling for OpenAI video resources, including detailed error propagation.
- Enhanced response structure to include OpenAI-specific fields for status, progress, and model mappings.
- Implemented new handlers for video content retrieval and error scenarios.
- Expanded test coverage to validate OpenAI video support, error handling, and backend compatibility.