compaction optimization

TS的compact性能优化，拆分为6个story：
1、添加ts端的性能测试：对接db_bench
2、抽象compact策略接口：简化后续添加不同的compact策略[2]
3、增加多线程compact，验证compact性能效果[3]
4、增加动态调分，验证写放到效果[1.5]
5、增加单个compact流程内的并行度，验证compact性能效果[3]
6、验证总体性能效果[2]

Start by locating the TS compaction implementation and the db_bench integration mentioned in the issue. Review how compaction is currently structured before assessing the six proposed stories: performance tests, strategy abstraction, multithreading, dynamic tuning, intra-compaction parallelism, and overall validation. Done is not defined beyond validating performance effects, so the scope and acceptance criteria need clarification.

Written by the indexing model from the issue text.