fix deepseek v3 model name

internal/handler/openrouter.go

@@ -12,9 +12,9 @@ var openRouterKey = os.Getenv("OP_Rowproxy_key")
 
 var openRouterModels = map[string]string{
 	"deepseek-r1":           "deepseek/deepseek-r1",
-	"deepseek-v3":           "deepseek/deepseek-v3-0324",
+	"deepseek-v3":           "deepseek/deepseek-v3-0324:free",
 	"deepseek-r1-0528":      "deepseek/deepseek-r1-0528",
-	"deepseek-v3-turbo":     "deepseek/deepseek-v3",
+	"deepseek-v3-turbo":     "deepseek/deepseek-v3:free",
 }
 
 func IsOpenRouterModel(model string) bool {