test: add naming configuration test

Exercises the naming option which was previously untested.
Verifies fields are applied to Sonarr via config/naming API
and validates idempotency (second run reports 'already correct').

tests/default.nix

@@ -13,4 +13,5 @@
   health-checks = import ./health-checks.nix { inherit pkgs lib self; };
   delayed-start = import ./delayed-start.nix { inherit pkgs lib self; };
   jellyseerr = import ./jellyseerr.nix { inherit pkgs lib self; };
+  naming = import ./naming.nix { inherit pkgs lib self; };
 }