Gate the license / next-steps message in the package postflight behind a
verification that every child extension declared in the manifest actually
installed. If any component/module/plugin is missing from #__extensions,
enqueue an error listing them instead of the success message. Fails open so
a transient glitch never fakes a failure; housekeeping runs unconditionally.
Claude-Session: https://claude.ai/code/session_01B9aZHSWbiiZykJD88pYx8R