common : --model or -hf is required

Assisted-by: Codex

common/arg.cpp

@@ -924,7 +924,7 @@ static bool common_params_parse_ex(int argc, char ** argv, common_params_context
         // TODO @ngxson : maybe show a list of available models in CLI in this case
         bool can_skip_model = params.usage || params.completion || !params.server_base.empty();
         if (!can_skip_model && params.model.path.empty()) {
-            throw std::invalid_argument("error: --model is required\n");
+            throw std::invalid_argument("error: --model or -hf is required\n");
         }
     }