Rename the Python package to daynivo_kiosk

src/voxip_kiosk -> src/daynivo_kiosk, with every import, the launchers,
install.sh, the Makefile and the manager's gunicorn app path. An upgrade
replaces /usr/lib/voxip-kiosk/python as a whole, so the old package
disappears; tested by upgrading an installation of the previous commit.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/test_validation.py

@@ -1,6 +1,6 @@
 import pytest
 
-from voxip_kiosk import validation as v
+from daynivo_kiosk import validation as v
 
 
 @pytest.mark.parametrize("url", [