Persist Adapters: All 15 MongoDB+Redis Implementations

PersistXAdapter.usePersistXAdapter(class implements IPersistXInstance {
  constructor(/* context fields from backtest-kit */) {}

  async waitForInit(initial: boolean) {
    if (!initial) return;
    await waitForInfra();  // gate first-touch on Mongo + Redis ready
  }

  async readXData(...) {
    return await ioc.xDbService.findByContext(...);
  }

  async writeXData(..., when: Date) {
    await ioc.xDbService.upsert(..., when);
  }
});