feat: add OverrideHostMiddleware to set HTTP_HOST from PUBLIC_URL environment variable and update nginx configuration

backend/server/main/settings.py

@@ -69,6 +69,7 @@ MIDDLEWARE = (
     'corsheaders.middleware.CorsMiddleware',
     'django.contrib.sessions.middleware.SessionMiddleware',
     'django.middleware.common.CommonMiddleware',
+    'adventures.middleware.OverrideHostMiddleware',
     'django.middleware.csrf.CsrfViewMiddleware',
     'django.contrib.auth.middleware.AuthenticationMiddleware',
     'django.contrib.messages.middleware.MessageMiddleware',