## What changed
- Add the disabled-by-default `image_resize_notice` feature.
- When enabled, append a developer message after resized images from user
messages or tool outputs. The notice identifies each image and reports its
original and prepared dimensions.
- Persist notices with new history while avoiding backfilled notices for images
processed when a session is resumed.
## Testing
- Cover notice placement, image numbering, failed images, user and tool image
sources, and resumed-session replay.
GitOrigin-RevId: 11dd808b3ad47eac35e9e2f4a4370f85d0122770