Spectreasy installer third-party notice

The packaged frontend dependency inventory is recorded in sbom.cdx.json and
is generated from inst/gui/package-lock.json at release time. R package
dependencies remain the package's declared CRAN/Bioconductor dependencies;
the installer uses the configured repositories only to satisfy those declared
dependencies during installation.

The Spectreasy source and binary package licenses and notices are included in
the package payload. No third-party executable or custom launcher binary is
distributed by this installer.
