优化结构

internal/logging/daily.go

@@ -50,6 +50,9 @@ func (w *DailyWriter) Write(value []byte) (int, error) {
 	defer w.mu.Unlock()
 	date := time.Now().Format("2006-01-02")
 	if w.file == nil || w.date != date {
+		// Retention is enforced again when a long-lived writer rolls to a new day.
+		// Running this only on rotation avoids a directory scan for every write.
+		w.removeExpired()
 		if w.file != nil {
 			_ = w.file.Close()
 		}