Hide LLM responses behind a config flag

...that we never use. I'm just turning it off for now, but I want the
linter to think it could be live at any moment.

platform/text/text.go

@@ -172,7 +172,9 @@ func respondText(ctx context.Context, log_id int32) error {
 		return nil
 	}
 	// Otherwise let the LLM handle the response
-	//return respondTextLLM(ctx, *src)
+	if config.DoLLMResponse {
+		return respondTextLLM(ctx, *src)
+	}
 	return nil
 }