Document self-registration toggle

stack.env.example

@@ -30,6 +30,10 @@ CSRF_TRUSTED_ORIGINS=https://yourdomain.com
 # Domain used in email links
 SITE_DOMAIN=yourdomain.com
 
+# Public self-registration toggle
+# Set to False to require admin-created accounts
+ALLOW_SELF_REGISTRATION=False
+
 # ===================================================================
 # Database Configuration (PostgreSQL)
 # ===================================================================
@@ -47,7 +51,7 @@ REDIS_URL=redis://redis:6379/0
 # ===================================================================
 # Email Configuration
 # ===================================================================
-# Required for user registration (email verification) and notifications
+# Required for email verification, approval emails, and notifications
 
 EMAIL_BACKEND=django.core.mail.backends.smtp.EmailBackend