[Feature Request] Improve plan review UI/UX with accessible side-by-side display mode

Feature Description
This is feedback for Claude Code Desktop (CCD):

TLDR; Redo the plan review UI/UX of offer side-by-side mode

Currently the UI/UX where Claude's thinking and past discussions if reduced to very dim text is inaccessible for those without perfect eyesight, and is hard to even access on smaller screens because the PLAN dialog takes so much space. We should be able to see them side-by-side instead other current overlay format.

It is so bad I try not to use the desktop version and instead use the terminal version because of the plan mode UI/UX.

Environment Info

• Platform: darwin
• Terminal: Apple_Terminal
• Version: 2.1.32
• Feedback ID: 3b84901a-76e6-4e37-b914-bae01d8e9628