added site modes

.env.example

@@ -18,3 +18,10 @@ FRONTEND_ORIGIN=
 # Frontend Configuration
 # URL of the backend API accessible from the frontend container.
 PUBLIC_API_URL=http://backend:3000
+
+# Presentation focus. Same skin either way (fonts, cybersigil/breakcore,
+# paper grain, CyberFx). `atelier` = image-first gallery (justified plates,
+# "plates" count). `blog` = writing-first (stacked rows, excerpt, reading
+# time). Read server-side at render — no rebuild needed to switch.
+# Anything other than `blog` falls back to atelier.
+SITE_MODE=atelier