feat(log): 解耦用户访问日志存储，支持切换日志主库

用户访问日志可在 ClickHouse、PostgreSQL、SQLite 之间切换。
关闭 ClickHouse 时由主库承接写入与查询；切换任务会冻结写入、复制数据后翻转主库。
启动时校验日志主库与运行配置一致，定期清理按各库保留天数删除过期记录。

internal/infra/task/handlers/register.go

@@ -6,6 +6,7 @@
 package handlers
 
 import (
+	"github.com/Rain-kl/Wavelet/internal/apps/admin/logs"
 	"github.com/Rain-kl/Wavelet/internal/apps/admin/push"
 	"github.com/Rain-kl/Wavelet/internal/apps/upload"
 	"github.com/Rain-kl/Wavelet/internal/apps/user"
@@ -35,4 +36,8 @@ func Register() {
 	// push
 	task.RegisterHandler(push.SendNotificationTask, &push.PushHandler{})
 	task.RegisterTaskMeta(push.SendNotificationMeta)
+
+	// logs
+	task.RegisterHandler(logs.LogDBSwitchTask, &logs.LogDBSwitchHandler{})
+	task.RegisterTaskMeta(logs.LogDBSwitchMeta)
 }