feat: notify configured recipients when something is booked

config/packages/twig.yaml

@@ -2,6 +2,10 @@ twig:
     file_name_pattern: '*.twig'
     # One theme for the whole app, so it is registered globally rather than per-template.
     form_themes: ['forms.html.twig']
+    paths:
+        # Mail templates embed the logo with email.image('@images/logo.png'), which needs the file
+        # on a Twig path -- an asset URL would be a remote image most clients block.
+        '%kernel.project_dir%/assets/images': images
 
 when@test:
     twig: