When a second display is connected (macOS), presenting now opens a
borderless audience window on the beamer showing the slide, while the
main window shows the presenter view (current/next slide, speaker notes,
clock, controls) on the laptop. The two windows stay in sync over method
channels: navigation, blank screen, audio-complete and beamer clicks are
forwarded between them, and media plays only on the beamer to avoid
double audio. Falls back to the existing single-window presenter when
there is one display or the second window can't be created.
- Vendors a fork of desktop_multi_window in third_party/ that re-adds the
native macOS window geometry/fullscreen calls (coverScreen, setFrame,
close) the published 0.3.0 dropped; wired via a path dependency.
- Registers the app's plugins for sub-windows in MainFlutterWindow so
video/image rendering works on the beamer.
- Routes the multi_window dart entrypoint to a minimal AudienceWindowApp.
Compiles (flutter analyze + macOS debug build) and all tests pass;
runtime two-screen behaviour still needs verification on real hardware.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
