adjust errors and logger (#10)

internal/wechat/key/windows/v3.go

@@ -1,20 +1,9 @@
 package windows
 
 import (
-	"errors"
-
 	"github.com/sjzar/chatlog/internal/wechat/decrypt"
 )
 
-// Common error definitions
-var (
-	ErrWeChatOffline    = errors.New("wechat is not logged in")
-	ErrOpenProcess      = errors.New("failed to open process")
-	ErrCheckProcessBits = errors.New("failed to check process architecture")
-	ErrFindWeChatDLL    = errors.New("WeChatWin.dll module not found")
-	ErrNoValidKey       = errors.New("no valid key found")
-)
-
 type V3Extractor struct {
 	validator *decrypt.Validator
 }