New features, and ScalPanel names everywhere.

- Mail: import a mailbox from another IMAP server; DKIM keys rotate on schedule; DMARC and SMTP TLS reports are collected and shown; MTA-STS for hosted domains.
- Sign-in: passkeys for panel users, and single sign-on (OIDC) for the provider's staff.
- Monitoring: uptime checks of an account's websites, public status pages, and alerts to Slack, Discord and Telegram.
- Security: country blocks in the provider's firewall and per website at the edge.
- Websites: HTTP/3 at the edge, container applications (run an image such as Ghost or n8n as a website), and WordPress smart updates that compare the pages before and after and roll back when they break.
- The panels can be installed as apps on phones and computers, with the reseller's own branding.
- Databases: choose the database server version where several are offered, and manage them in the browser with the database manager (Adminer) for MariaDB, PostgreSQL and MongoDB. It runs on port 2092: open it in the server's firewall.
- ScalWS is the web server of new installations; installed servers keep theirs. Sections that only apply to nginx are shown only with nginx.
- The last vPanel names are gone. After this update the server moves its databases, their users and its Docker volumes to the ScalPanel names by itself: the panels and mail stop for a few minutes once, websites keep running. If the move cannot finish, it is undone and can be retried with `scalpanelctl move-names`.
- Everyone signs in again once after the update (the session cookies have new names).
- New API tokens start with `spt_`; existing `vpt_` tokens keep working. Webhooks send `X-ScalPanel-*` headers and, for now, the old `X-VPanel-*` ones too.
- Updates now come from https://releases.scalws.com.
- Billing modules are now named `scalpanel` (WHMCS and Blesta). An installed `vpanel` module keeps working; switch products to the new one when convenient.
- This update needs ScalPanel 0.1.23 or newer; older servers update to 0.1.28 first.