- One executable per architecture: x86_64 built with llvm-mingw against
  msvcrt for Windows 7 SP1, aarch64 for Windows 11 on Arm; a small shim answers
  the few Windows 8+ imports.
- draw builds wgpu and OpenGL 2.1 side by side on Windows and picks D3D12 where
  it exists, OpenGL elsewhere.
- The title bar follows the system: Mica with system caption hit-testing on 11,
  a drawn caption over Acrylic on 8 and 10, the system frame on 7.
- Section files open with OneNote's share modes and one-byte locks, so
  Snowbound and OneNote 2010 edit one notebook side by side, locally and over
  UNC shares.
- Dialogs, Credential Manager, ReadDirectoryChangesW, MCI audio, spelling,
  icon and manifest; releases publish Windows builds that update themselves.
- Also: the Windows 10 and 11 lab VMs, Bonjour share names, redrawn sync icons
  with a mount-fallback warning, symlinked mount detection, and fixes for
  modifier timing, tied edit clocks, and folder syncing on Windows.

Assisted-by: claude-opus-5.5