Force PostGIS backend using dictionary spread syntax

- Use **db_config spread syntax to ensure PostGIS engine override takes effect
- This prevents dj_database_url from overriding the PostGIS backend setting

thrillwiki/settings.py

@@ -93,18 +93,19 @@ WSGI_APPLICATION = "thrillwiki.wsgi.application"
 
 # Database
 
-# Parse database URL but use PostGIS engine
+# Parse database URL but force PostGIS engine
 db_config = dj_database_url.config(
     default="[DATABASE-URL-REMOVED]
     conn_max_age=600,
     conn_health_checks=True,
 )
 
-# Override engine to use PostGIS
-db_config["ENGINE"] = "django.contrib.gis.db.backends.postgis"
-
+# Force PostGIS engine - override any parsed engine
 DATABASES = {
-    "default": db_config
+    "default": {
+        **db_config,
+        "ENGINE": "django.contrib.gis.db.backends.postgis",
+    }
 }
 
 # Cache settings