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>

ansible/roles/podman/files/debyltechmail/appinfo/info.xml

@@ -0,0 +1,44 @@
+<?xml version="1.0"?>
+<info xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+      xsi:noNamespaceSchemaLocation="https://apps.nextcloud.com/schema/apps/info.xsd">
+    <id>debyltechmail</id>
+    <name>de Byl Tech Customisations</name>
+    <summary>de Byl Technologies-branded email templates and UI overrides for Nextcloud and LibreSign</summary>
+    <description><![CDATA[
+Restyles outgoing Nextcloud and LibreSign mail to match the de Byl
+Technologies brand (~/src/debyltech/debyltech-com). Cloned from the Skudak
+instance's skudakmail app. Two supported extension points, no core
+patch and no LibreSign fork:
+
+1. `OCA\Debyltechmail\Mail\DebyltechEMailTemplate` extends Nextcloud's EMailTemplate
+   and is wired in via the `mail_template_class` system config value, which
+   Nextcloud checks in `lib/private/Mail/Mailer.php::createEMailTemplate()`.
+   It owns layout, typography, subject rewriting, button labels and the
+   footer LibreSign never adds.
+
+2. `OCA\Debyltechmail\Listener\DebyltechMailListener` listens on
+   `OCP\Mail\Events\BeforeMessageSent` to embed the wordmark as an inline
+   (cid:) MIME part, so the logo survives the remote-image blocking that
+   Apple Mail, Gmail and Outlook apply by default. This cannot be done from
+   the template class, which has no reference to the message.
+
+3. `OCA\Debyltechmail\Listener\DebyltechStyleListener` listens on
+   `OCP\AppFramework\Http\Events\BeforeTemplateRenderedEvent` and adds
+   css/libresign-mobile.css, which fixes the LibreSign public signing page
+   being clipped at the bottom on iOS Safari. Serving it from here rather
+   than patching LibreSign keeps the app's integrity signature intact and
+   survives app updates, which wipe the app directory.
+
+The app has no routes, no UI, no settings and no database tables. The id
+`debyltechmail` is referenced by the `mail_template_class` system config;
+its scope is instance-wide customisation, not mail alone.
+    ]]></description>
+    <version>1.0.0</version>
+    <licence>agpl</licence>
+    <author>de Byl Technologies LLC</author>
+    <namespace>Debyltechmail</namespace>
+    <category>customization</category>
+    <dependencies>
+        <nextcloud min-version="34" max-version="34"/>
+    </dependencies>
+</info>