The predecessor's image carried .venv/scripts/flask.sh, created by a
build step that never made it into the files this module holds — the
image worked and its recipe could not reproduce it, caught the moment
the mesh built it from source (exit 127 crash loop at cutover). The
wrapper is now written explicitly, verbatim from the proven image, so
the recipe is the whole truth about the image.
jschoubben