[rennf93]

Closes #59

I removed the keys.sort() from list_keys in RedisClientHandler and InMemoryRedisStore (src/persistence.rs). list_keys is only used by the startup reload, so reload now iterates keys in the order the store returns them, as the Python reference does (_load_events_from_redis / _load_metrics_from_redis). The reference only sorts on its limited clear path, which has no counterpart here (clearing is by explicit key or whole namespace). The InMemoryRedisStore::keys inspection helper stays sorted. The over-capacity handling on reload (evict the oldest buffered item before pushing) already matches the reference. The key stamp is SystemTime epoch nanoseconds, matching time.time_ns(). No docs claimed oldest-first reload, and no test assumed sorted reload.

Gate run locally: fmt, clippy -D warnings, tests (default and all features with --include-ignored against Redis), docs, MSRV 1.92 check and test, and the 100% line coverage gate all exit 0.