fix: #3637289 Use a PNG logo in HTML emails instead of the SVG site logo

Issue: https://www.drupal.org/i/3637289

HTML emails use the SVG site logo, which Gmail and Outlook do not show. This ships config/easy_email_theme.settings.yml pointing the Easy Email Theme logo at the Vartheme BS5 PNG (themes/contrib/vartheme_bs5/logo-email.png).

It is a config file, not a config action: Easy Email Theme ships no default settings, and simpleConfigUpdate cannot create missing config. Recipes only create config that does not exist yet, so sites that already set a logo keep it.

Needs the Vartheme BS5 PNG (#3637288) released first. Until then the path points at a missing file and emails show no logo.

Testing

1. Install Varbase Starter with the Vartheme BS5 MR in place.
2. drush config:get easy_email_theme.settings shows use_default: false and the PNG path.
3. Send a password reset email and open it in Mailpit: the logo <img> is logo-email.png and HTML Check lists no SVG warning.

Remaining tasks

• MR pipeline green. YAML lint passed here, and Composer validate, ESLint, CSpell and the Cucumber dry-run passed locally; the install job timed out reaching Launchpad (add-apt-repository), so the functional jobs were skipped. Rerun once Launchpad is reachable.

AI-Generated: Yes

Checkpoints:

• File an issue
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• Release notes snippet
• Release