v0.4.2

Updates that know which package you installed.

Changed

neonrp and worldlines update separately: running neonrp checks and
upgrades the engine only; running worldlines upgrades the shell shim, which
pulls the engine version it pins. /update apply in the TUI follows the same
rule instead of always upgrading neonrp.
The neonrp launcher now shows the same "new version available" banner the
worldlines launcher had.
releases.json carries one version per package (packages.neonrp,
packages.worldlines); the old top-level latest stays for older clients and
follows the shell shim.

World exports include the project manifest again, so Hub downloads and
imports of template-style worlds work.
Stub-model and timeout test expectations aligned with the shipped behaviour.

pip install -U neonrp