Add developer application page with form submission that creates tickets
in SilverDESK. Includes provisioning service scaffolding for Mattermost,
Mailcow, and Gitea account creation. Fixes API key header casing
(X-API-Key) and ticket payload to match SilverDESK's CreateTicketDto
contract.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
