feat: 优化代理服务

internal/utils/string_utils.go

@@ -0,0 +1,12 @@
+package utils
+
+import "fmt"
+
+// MaskAPIKey masks an API key for safe logging.
+func MaskAPIKey(key string) string {
+	length := len(key)
+	if length <= 8 {
+		return key
+	}
+	return fmt.Sprintf("%s****%s", key[:4], key[length-4:])
+}