Drop-in scaffolding for any Windows desktop app built on Rust +
eframe/egui. Ships: eframe single-window app with dark-mode default,
JSON config persisted to %APPDATA%, build.rs
reading the latest git tag and exposing APP_VERSION, WiX
MSI installer with MajorUpgrade plus a Desktop shortcut, and a
self-update mechanism polling GitHub Releases.
scripts/new_app.ps1 mints a new app at a target path
with token rewrites and fresh WiX GUIDs.