[Feature Request] Add visual separator/box for message boundaries to improve readability

Bug Description
I'd like my messages to be much more prominent. I often cannot find the top of the response because it all looks the same. You need to make a big wide bright box so our eyes can track to the top of the message

Environment Info

• Platform: darwin
• Terminal: Apple_Terminal
• Version: 2.1.49
• Feedback ID: 7ee4a4fe-a656-4604-8c9e-51ecfe304dca

Errors

[{"error":"Error: Request was aborted.\n    at NhR (/$bunfs/root/claude:1375:50906)\n    at next (native:1:11)\n    at InB (/$bunfs/root/claude:5008:5869)\n    at next (native:1:11)\n    at YnB (/$bunfs/root/claude:5013:9284)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-02-21T22:51:10.492Z"}]