web-app-wordpress: move msmtp configuration from Docker image to docker-compose mount

- Removed COPY of msmtp configuration from Dockerfile to avoid baking secrets/config into the image
- Added volume mount for host-side msmtp config ({{ WORDPRESS_HOST_MSMTP_CONF }}) in docker-compose.yml
- Keeps PHP upload.ini handling inside the image, but externalizes sensitive mail configuration
- Increases flexibility and avoids rebuilds when msmtp config changes

Ref: https://chatgpt.com/share/68af3c51-0544-800f-b76f-b2660c43addb

roles/web-app-wordpress/templates/Dockerfile.j2

@@ -10,6 +10,5 @@ RUN curl -O https://raw.githubusercontent.com/wp-cli/builds/gh-pages/phar/wp-cli
     chmod +x wp-cli.phar && \
     mv wp-cli.phar /usr/local/bin/wp
 
-# Copy msmtp configuration and PHP upload settings
-COPY config/msmtprc.conf /etc/msmtprc
+# Copy PHP upload settings
 COPY upload.ini $PHP_INI_DIR/conf.d/

roles/web-app-wordpress/templates/docker-compose.yml.j2

@@ -9,6 +9,7 @@
       - "127.0.0.1:{{ ports.localhost.http[application_id] }}:80"
     volumes:
       - data:{{ WORDPRESS_DOCKER_HTML_PATH }}
+      - {{ WORDPRESS_HOST_MSMTP_CONF }}:/etc/msmtprc
 
 {% include 'roles/docker-container/templates/healthcheck/msmtp_curl.yml.j2' %}
 {% include 'roles/docker-container/templates/depends_on/dmbs_excl.yml.j2' %}