fullscreen: "1 new message" banner stays after scrolling back to the bottom

in fullscreen mode the ─── 1 new message ─── banner above the prompt does not go away once i have scrolled back down and read everything. it read 1 the whole time it was up.

env:

• macos 26.5.2 (25F84), arm64
• claude code 2.1.235
• ghostty 1.3.1, inside tmux, TERM=tmux-256color
• fullscreen rendering on, default settings

repro:

1. scroll up while a turn is streaming
2. ctrl+o, then [ to print to scrollback, then esc
3. scroll back down to the bottom

expected: banner clears once i am at the bottom with nothing unread.

actual: banner stays for the rest of the session, still reading "1 new message".