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/testhelper/test_helper.go

@@ -282,6 +282,36 @@ func getSeedConfigsPart2() []model.SystemConfig {
 			Type:        configTypeSystem,
 			Description: "文件存储驱动及连接配置（JSON）",
 		},
+		{
+			Key:         model.ConfigKeyLogDatabase,
+			Value:       "sqlite",
+			Type:        configTypeSystem,
+			Description: "当前日志主库",
+		},
+		{
+			Key:         model.ConfigKeyLogDBMigration,
+			Value:       "",
+			Type:        configTypeSystem,
+			Description: "日志库迁移冻结标记",
+		},
+		{
+			Key:         model.ConfigKeyLogRetentionDaysPostgres,
+			Value:       "30",
+			Type:        "business",
+			Description: "PostgreSQL 用户访问日志保留天数",
+		},
+		{
+			Key:         model.ConfigKeyLogRetentionDaysSQLite,
+			Value:       "30",
+			Type:        "business",
+			Description: "SQLite 用户访问日志保留天数",
+		},
+		{
+			Key:         model.ConfigKeyLogRetentionDaysClickHouse,
+			Value:       "30",
+			Type:        "business",
+			Description: "ClickHouse 用户访问日志保留天数",
+		},
 	}
 }