fix: Support the v2 harness persistence config shape and daemon mode in the contract test service

[joker23]

Summary

The contract test service only read the persistence configuration from the FDv2 shape (dataSystem.store.persistentDataStore). The v2 test harness sends it at the top level of the SDK configuration, so no persistent store was constructed at all under that harness: the SDK ran on the in-memory store, the $inited marker was never written, and every read-write persistence test failed.

• Read the top-level persistentDataStore configuration and map it to the FDv1 featureStore option. One code path serves both the Redis and DynamoDB store types.
• When a persistent store is configured with neither streaming nor polling, enable daemon mode (useLdd). This is the faithful translation of the harness's store-without-sources configuration, matches the Go test service (ExternalUpdatesOnly), and stops the entity from dialing production LaunchDarkly with the test credential in those scenarios.
• Wait for the Redis client's ready event before handing it to the store. The entity disables the offline queue, so commands sent before the connection is ready fail immediately and can race the SDK's first writes.
• Suppress the FDv2 no-data-source persistence tests: the FDv2 store-read mode with zero sources does not complete initialization yet.

Verified locally against the full v2 and v3 harness suites with Redis and DynamoDB running: all persistence tests pass (v2) or are explicitly suppressed (v3 no-data-source set).

---

Note

Overview
Fixes the Node server contract-test entity so v2 harness persistence scenarios work: it now reads top-level persistentDataStore (not only dataSystem.store) and maps it to FDv1 featureStore, with useLdd when there is a store but no streaming/polling (daemon mode).

Redis persistence is built with an explicit ioredis client (new dependency), waits for ready before the SDK writes, and closeStore tears down the connection on client shutdown or init failure. DynamoDB sets maxAttempts: 1 so harness outage simulations aren’t masked by AWS retries. makeSdkConfig is async and returns { config, closeStore }; FDv2 paths also enable dataSystem.useLdd when there are zero data sources.

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@launchdarkly/js-client-sdk size report
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@launchdarkly/js-client-sdk-common size report
This is the brotli compressed size of the ESM build.
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Uncompressed size: 165420 bytes

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