Captured on prod with a second collaborator account (Zoraya Shahin):
chapter 12 shows Nadia's bell after a watched-page comment, chapter 13
shows the presence strip + Zoraya's named caret in Nadia's editor.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0155v2aT8AG1kZDQEZiCLBWC
