release.yml builds four platforms and publishes a release, which is right for a
release and slow for 'give me an exe to test'. Wall time is set by the Windows
job, which compiles native modules and downloads Electron twice because it
targets x64 and arm64 together — and Windows-on-ARM is not something this group
runs.
This path builds one architecture, caches the Electron and electron-builder
downloads (~100MB re-fetched every run otherwise), and uploads the installer as
an artifact, so it needs neither a tag nor a version bump.
Kept as a separate file: release.yml comes from upstream and takes merges, so
editing it would conflict on every update.
Cost matters too on a private repository: macOS runners bill at 10x and Windows
at 2x, so the full matrix was paying for macOS builds on every tag.
