Chalkboard: annotations in speaker view are not mirrored to main presentation

Bug description

When using the chalkboard feature and adding some annotations in a speaker view setting, the annotations are not mirrored to the main presentation.

This is an issue as usually one looks at the speaker view during a presentation on the laptop while the main audience looks at the mirrored slides behind/beside the speaker. For speakers, it's not easy to spot that things are not synchronized.

Adding annotations only on the main presentation view would require taking the mouse across screens which is fiddly and takes additional time.

quarto v1.1.120

Checklist

• Please include a minimal, fully reproducible example in a single .qmd file? Please provide the whole file rather than the snippet you believe is causing the issue.
• Please format your issue so it is easier for us to read the bug report.
• Please document the RStudio IDE version you're running (if applicable), by providing the value displayed in the "About RStudio" main menu dialog?
• Please document the operating system you're running. If on Linux, please provide the specific distribution.

The issue names no source files, tests, or entry points. Start by reproducing the chalkboard behavior in speaker view and the main presentation, then trace how annotations are synchronized between them. Done means annotations added in speaker view appear on the main presentation.