ui5:assemble {blueprint} — the self-contained assembly command (spec §5),
the flagship consumer of the generator surface.
One self-contained app, fixed name Showcase (D9): no {name} argument, no
legacy prefix/title/vendor options. The namespace root + vendor are declared
as public const on this command (KISS) — the Showcase app is a single
teaching on-ramp (the Breeze precedent), not an app factory; the consumer
owns every generated file and renames post-gen if they wish. The production
path for many apps is ui5:app + PackageStrategy.
It orchestrates the leaf generators (D10): after emitting the blueprint's
static files it invokes ui5:tile/ui5:chart with deterministic names,
dogfooding the --seed catalog. The blueprint ships a pre-wired Module
(plus Dashboard + Group) whose registrations already reference those exact
namespaces, so the app boots onto a working dashboard from one command.