docs(readme): platform shot — capture the REAL chat-everywhere two-pane (one window)

Render the actual Home two-pane (chat conversation + staged workflow) in one
capture instead of stitching two views — correct window ratio and the real
single divider, framed on off-white grey.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: andresdjasso