frigate: gate frontend with Authelia, not just API routes

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

services/frigate.nix

@@ -94,6 +94,13 @@
         '';
       };
 
+      # The Frigate module serves the frontend from "/" without auth_request,
+      # so unauthenticated users see a broken loading page instead of being
+      # redirected to Authelia. Gate it behind auth too.
+      locations."/".extraConfig = lib.mkAfter ''
+        auth_request /auth;
+      '';
+
       # Redirect 401 → Authelia login portal
       extraConfig = lib.mkAfter ''
         error_page 401 =302 https://auth.nordhammer.it/?rd=$scheme://$http_host$request_uri;