core: status: add permission denied status code

core/include/blue/core/status.h

@@ -21,6 +21,7 @@ typedef enum b_status {
 	B_ERR_IO_FAILURE,
 	B_ERR_IS_DIRECTORY,
 	B_ERR_NOT_DIRECTORY,
+	B_ERR_PERMISSION_DENIED,
 } b_status;
 
 BLUE_API const char *b_status_to_string(b_status status);