Store correctness contract test suite (#212)

* Add Store correctness contract test suite

Defines a run_contract_suite() function that tests every observable
behaviour of a Store implementation:

  - Empty-store edge cases (range query, exact query, earliest timestamp)
  - Single insert: range query hit/miss, exact query hit/miss (wrong start,
    wrong end)
  - Batch insert: count correctness, chronological ordering guaranteed
  - Partial range filtering (windows outside query range excluded)
  - Aggregation-ID isolation (inserts into agg 1 not visible to agg 2)
  - Earliest-timestamp tracking: global minimum, per agg-ID
  - Cleanup — CircularBuffer: oldest window evicted, newest 8 retained
  - Cleanup — ReadBased: evicted after threshold reads, unread window kept
  - Concurrency: 8-thread concurrent inserts (no data loss),
    8-thread concurrent reads (each returns full result set)

Two test entry points exercise both existing implementations:
  contract_per_key  — LockStrategy::PerKey (reference)
  contract_global   — LockStrategy::Global

Adding a new Store implementation requires only a new #[test] function
that calls run_contract_suite() with the new factory.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* Extend store contract tests: all accumulator types, keyed entries, DeltaSet exclusion

- Add SerializableToSink import so clone-fidelity tests compile on concrete types
- Clone fidelity tests for all 11 accumulator types: SumAccumulator,
  MinMaxAccumulator, DatasketchesKLLAccumulator, IncreaseAccumulator,
  MultipleSumAccumulator, MultipleMinMaxAccumulator, SetAggregatorAccumulator,
  DeltaSetAggregatorAccumulator, CountMinSketchAccumulator,
  CountMinSketchWithHeapAccumulator, HydraKllSketchAccumulator
- Three keyed-entry tests: grouping by key, coexistence of keyed/unkeyed, multiple keys per window
- DeltaSetAggregator cleanup exclusion test
- Concurrency tests: concurrent inserts (8 threads) and concurrent reads

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* Fix cargo fmt violations in store_correctness_tests

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* Remove unused assert_clone_fidelity function (clippy dead_code)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* Fix extra blank line (cargo fmt)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: zzylol

asap-query-engine/src/tests/mod.rs

@@ -4,6 +4,7 @@ pub mod elastic_forwarding_tests;
 pub mod prometheus_forwarding_tests;
 pub mod query_equivalence_tests;
 pub mod sql_pattern_matching_tests;
+pub mod store_correctness_tests;
 pub mod trait_design_tests;
 
 #[cfg(test)]