True when the HOST is an unpackaged dev build (!app.isPackaged) — the
host-build flavor, NOT this project's §3.18 effective bundle mode. Rides
the theme frame because that is the hello-reply bootstrap seam. Omitted by
an older host; consumers treat absence as "unknown", not false.
True when the HOST is an unpackaged dev build (
!app.isPackaged) — the host-build flavor, NOT this project's §3.18 effective bundle mode. Rides the theme frame because that is the hello-reply bootstrap seam. Omitted by an older host; consumers treat absence as "unknown", not false.