226fe87345
- Implemented strict base64 validation and normalization for image `displayValue` payloads in the JS runtime, supporting strict strings, `Uint8Array`, `Buffer`, `ArrayBuffer`, typed-array views, and JSON `Buffer` objects. - Dropped unrecognized image payloads while emitting a warning and fallback text instead of forwarding malformed data. - Added tests covering successful coercions and invalid image data rejection paths.