Rename the visible VoxIP texts to Daynivo

Product name (Daynivo Kiosk OS), default device name, kiosk screens,
service descriptions, installer output and docs. Internal names
(voxip-kiosk-*, /etc/voxip-kiosk, user voxip, VOXIP_* variables) stay.
An update renames a device still called "VoxIP Kiosk" to the new default.

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

pyproject.toml

@@ -1,7 +1,7 @@
 [project]
 name = "voxip-kiosk"
 dynamic = ["version"]
-description = "VoxIP Kiosk OS — kiosk runtime and Daynivo Kiosk Manager"
+description = "Daynivo Kiosk OS — kiosk runtime and Daynivo Kiosk Manager"
 requires-python = ">=3.11"
 
 [tool.pytest.ini_options]