fix: enforce apex redirect using Host header

mandelstudio/middleware.py

@@ -14,7 +14,9 @@ class RedirectApexToWwwMiddleware:
         self.get_response = get_response
 
     def __call__(self, request: HttpRequest):
-        host = (request.get_host() or "").split(":")[0].lower()
+        # Use the raw Host header so proxy-specific X-Forwarded-Host rewrites
+        # can't prevent the apex redirect.
+        host = (request.META.get("HTTP_HOST") or "").split(":")[0].lower()
         if host == "mandelblog.com":
             destination = request.build_absolute_uri().replace(
                 "://mandelblog.com", "://www.mandelblog.com", 1