fix: correct CEL syntax for subscription_info has() check

Fix CEL syntax error in AuthPolicy subscription_info field that was causing
AuthConfig validation failures and blocking model access.

The has() macro in Authorino/Kuadrant CEL does not support map subscript
notation has(auth.metadata["subscription-info"]). Changed to check for a
specific field within the object: has(auth.metadata["subscription-info"].name).

Error message before fix:
  ERROR: <input>:1:18: invalid argument to has() macro
   | has(auth.metadata["subscription-info"]) ? ...
   | .................^

This was causing AuthPolicies to remain in Enforced=False state, preventing
smoke tests from passing.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: jrhyness

maas-controller/pkg/controller/maas/maasauthpolicy_controller.go

@@ -481,7 +481,7 @@ allow {
 								// Contains: name, namespace, labels, organizationId, costCenter, error, message
 								// Consumers should access nested fields (e.g., subscription_info.organizationId)
 								"subscription_info": map[string]interface{}{
-									"expression": `has(auth.metadata["subscription-info"]) ? auth.metadata["subscription-info"] : {}`,
+									"expression": `has(auth.metadata["subscription-info"].name) ? auth.metadata["subscription-info"] : {}`,
 								},
 								// Error information (for debugging - only populated when selection fails)
 								"subscription_error": map[string]interface{}{