feat(debyltech-cloud): add cloud.debyltech.com Nextcloud

A de Byl Technologies LLC Nextcloud cloned from the Skudak instance:
LibreSign signing for people without an account, registration off
(admin-created accounts only), no Group Folders. DNS is a terraform-managed
ALIAS to fulfillr.debyltech.com.

- containers/debyltech/cloud.yml: nextcloud/mariadb/redis on port 8091.
  It installs unattended on the first deploy, sends mail through SES as
  noreply@debyltech.com, and re-asserts the Skudak LibreSign settings.
- files/debyltechmail: skudakmail rebranded, with a new black-and-white
  wordmark and white web-UI logos.
- LibreSign is pinned to 14.2.2 from the GitHub release (sha256-checked)
  rather than `occ app:install`. The app store served a same-day 14.2.3
  whose tarball has no binary-signature metadata. 14.2.x also doesn't
  create its own download dirs, so they're pre-created.
- The backup runs nightly at 04:15 to TrueNAS /mnt/glacier/debyltechcloud and
  reaches personal iDrive via the "iDrive E2 Backup" task; the TrueNAS side
  excludes /debyltechcloud/_backup/config/**.
- Fix the libresign:configure:check gate in both instances: '\berror\b'
  becomes a backspace in Jinja and never matched, so a check reporting three
  errors passed clean. Now '\\berror\\b'.
- vault: cloud_debyltech_* secrets.

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

CLAUDE.md

@@ -60,7 +60,7 @@ ansible/
 Containers are organized in `ansible/roles/podman/tasks/containers/`:
 - `base/` - Core infrastructure containers (Caddy web server, AWS DDNS)
 - `home/` - Home-specific services (Home Assistant, PartKeepr, Immich photos, Nextcloud, Redis)
-- `debyltech/` - Personal/business services (Fulfillr)
+- `debyltech/` - Personal/business services (Fulfillr, Nextcloud at cloud.debyltech.com - cloned from the Skudak instance, backs up to personal iDrive via TrueNAS)
 - `skudak/` - Additional services (BookStack wiki, Nextcloud)
 
 ### Security Model