- Add contextUsageEvent case handler in kiro_executor.go for both
parseEventStream and streamToChannel functions
- Handle nested format: {"contextUsageEvent": {"contextUsagePercentage": 0.53}}
- Keep KiroModel struct minimal with only essential fields
- Remove unused KiroPromptCachingInfo struct from kiro_model_converter.go
- Remove unused SupportedInputTypes and PromptCaching fields from KiroAPIModel