fix: default openrouter key from env

scripts/fetch_openrouter.go

@@ -93,7 +93,7 @@ func main() {
 
 func parseArgs() Config {
 	loadProjectEnv()
-	apiKey := flag.String("api-key", "", "OpenRouter API Key")
+	apiKey := flag.String("api-key", os.Getenv("OPENROUTER_API_KEY"), "OpenRouter API Key")
 	apiURL := flag.String("api-url", "https://openrouter.ai/api/v1/models", "API 地址")
 	outPath := flag.String("out", "models.json", "输出文件路径")
 	maxRetries := flag.Int("retry", 3, "最大重试次数")