The update Download button opened the GitHub release page; it now
downloads the right artifact for the running platform directly: arm64
or x64 dmg on macOS (preload newly exposes process.arch), the Setup exe
on Windows. Linux keeps the release page since it ships three formats
and the user picks. Unknown platforms and preloads without arch fall
back to the page. URL mapping is unit-tested per platform.
Co-authored-by: reviewer <review@local>
Checks the GitHub releases for newer desktop-v tags once per launch
and every 24h (15s timeout, no identifying headers, offline = silent
retry). A dismissible banner and a Settings About row surface the
newer version and link the release page; dismissal persists per
version so each release nags at most once. No auto-install: unsigned
builds cannot, by platform constraint; the checker only notifies.
App 364/364 (+24), typechecks + build green.