build-deb.sh used 'cp -r app/ source/' which renames app to source
when source doesn't yet exist, dropping the app/ wrapper that the
Dockerfile's COPY app/ /app/ depends on. The 2>/dev/null || true
on the cp lines hid the resulting failures, so the .deb shipped a
broken /opt/dupfinder/source/ that build-from-source could not use.
Pre-create the source dir and copy each item to its explicit
destination path. Bump package version to 1.0.1.
Also rework dupfinder-setup.sh's image-prep step: prefer a local
image, then a quiet registry pull, then build from the bundled
source. Removes the loud registry-not-found error that scared users
when the (unpublished) tocmo0nlord/dupfinder image wasn't on Docker
Hub.
077fbd7e8f