[Feature Request] Highlight plan differences between iterations in plan mode

When using plan mode, I often need to request adjustments to the suggested plan. After declining and describing the changes I want, a revised plan is generated.

Currently, I have to re-read the entire plan to verify what changed and whether my requested adjustments were applied correctly. It would be very helpful to have the differences highlighted (similar to a diff view), so I can quickly see exactly what was modified between plan iterations.