## What changed
- Add the disabled-by-default `omit_app_server_notification_media` feature.
- When enabled, remove inline image and audio content from `item/started`,
`item/completed`, and `rawResponseItem/completed` notifications, including
tool output and image-generation results.
- Keep the media in model input; the filter only changes app-server
notifications.
## Testing
- Verify that image content is absent from all three notification types while
the model request still receives it.
GitOrigin-RevId: 9a4434d18a3dac6d67c2e0c3723ff4595a9b3797