Closes#704
Add support for base64-encoded image data in the look_at tool,
enabling analysis of clipboard/pasted images without requiring
a file path.
Changes:
- Add optional image_data parameter to LookAtArgs type
- Update validateArgs to accept either file_path or image_data
- Add inferMimeTypeFromBase64 function to detect image format
- Add try/catch around atob() to handle invalid base64 gracefully
- Update execute to handle both file path and data URL inputs
- Add comprehensive tests for image_data functionality
d099b0255f