New TurnKey Znuny version (19.0)

Changes:

• Update the appliance base to Debian 13 (Trixie).
• Install the security-supported Znuny 6.5 LTS package from Debian and use its current permissions and cron contracts.
• Replace the CPAN build-time dependency with the Debian Mozilla CA package.
• Create the separately branded Znuny appliance while retaining Debian's package-owned OTRS-compatible runtime interfaces.
• Add a Debian package updater and v19 acceptance coverage for agent login, queues, mail-created tickets, MariaDB, background jobs, and local mail.
• Replace historical product artwork with a neutral TurnKey Znuny badge and document its provenance and non-endorsement boundary.

Links

• Release meta-files (signature, manifest)