adjust errors and logger (#10)

internal/wechat/decrypt/decryptor.go

@@ -2,7 +2,6 @@ package decrypt
 
 import (
 	"context"
-	"fmt"
 	"io"
 
 	"github.com/sjzar/chatlog/internal/errors"
@@ -10,12 +9,6 @@ import (
 	"github.com/sjzar/chatlog/internal/wechat/decrypt/windows"
 )
 
-// 错误定义
-var (
-	ErrInvalidVersion      = fmt.Errorf("invalid version, must be 3 or 4")
-	ErrUnsupportedPlatform = fmt.Errorf("unsupported platform")
-)
-
 // Decryptor 定义数据库解密的接口
 type Decryptor interface {
 	// Decrypt 解密数据库