refactor(log): remove legacy log deletion endpoint and associated types

controller/log.go

@@ -150,6 +150,10 @@ func GetLogsSelfStat(c *gin.Context) {
 	return
 }
 
+// DeleteHistoryLogs is the legacy synchronous log cleanup endpoint (DELETE /api/log/).
+// It deletes directly instead of going through the async system task. It is kept only
+// for the classic frontend; the default frontend uses POST /api/system-task/log-cleanup.
+// TODO: remove this handler (and its route) once the classic frontend is removed.
 func DeleteHistoryLogs(c *gin.Context) {
 	targetTimestamp, _ := strconv.ParseInt(c.Query("target_timestamp"), 10, 64)
 	if targetTimestamp == 0 {