Style newsletters and system e-mails like www.eom.dev

Catppuccin Mocha campaign template (default) and archive variant, kept
in sync in the database; system e-mail header/footer overridden via
--static-dir from a ConfigMap. PNG logo for mail clients. Tested in
Mailpit (desktop, phone width; 87% CSS support, rest inlined).

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

tests/render.yml

@@ -29,9 +29,9 @@
         src: "{{ role_path }}/templates/{{ item }}.j2"
         dest: "{{ out }}/{{ item }}"
         mode: "0600"
-      loop: [secret.yml, postgres.yml, listmonk.yml, configure.sql]
+      loop: [secret.yml, postgres.yml, listmonk.yml, configure.sql, email-configmap.yml]
     - name: Manifests parse as YAML
       ansible.builtin.assert:
         that: lookup('ansible.builtin.file', out ~ '/' ~ item) | from_yaml_all | list | length > 0
         quiet: true
-      loop: [secret.yml, postgres.yml, listmonk.yml]
+      loop: [secret.yml, postgres.yml, listmonk.yml, email-configmap.yml]