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>

image/build.sh

@@ -72,7 +72,7 @@ VOXIP_DEFAULT_URL=$(printf %q "$VOXIP_DEFAULT_URL")
 VOXIP_DEVICE_NAME=$(printf %q "$VOXIP_DEVICE_NAME")
 EOF
 cat > "$PAYLOAD/BUILD-INFO" <<EOF
-voxip_kiosk_os=$VERSION
+daynivo_kiosk_os=$VERSION
 source_revision=$SOURCE_REV
 pi_gen_ref=$PI_GEN_REF
 pi_gen_commit=$PI_GEN_COMMIT