Greptile Summary

This PR adds a touch() method across all cache adapters and the Cache facade, allowing callers to refresh an entry's timestamp without replacing its data. The implementation is complete and well-structured for the simpler adapters (Memory, Filesystem, None, Pool, Sharding).

• Redis and RedisCluster implement touch() as a hGet → update time → hSet sequence; this is non-atomic, so a concurrent save() call on the same key between those two operations will have its payload silently overwritten by the stale data read during touch().
• Memcached and Hazelcast have the same non-atomic get→set pattern, making them susceptible to the same concurrent-write data corruption.
• The shared test in Base::testCacheTouch() correctly validates the core TTL-refresh behavior (save, sleep past TTL, confirm expired, touch, confirm accessible) and the missing-key false-return path.

Confidence Score: 4/5

Safe to merge for single-writer workloads; concurrent save+touch on the same key in Redis, RedisCluster, Memcached, or Hazelcast can silently revert a just-saved payload to stale data.

The non-atomic read-modify-write in the network-backed adapters (Redis, RedisCluster, Memcached, Hazelcast) introduces a window where a concurrent save() can be overwritten by touch() with old payload content. The race is unlikely in low-concurrency deployments but is a real correctness concern in high-throughput environments where the same key is updated and touched simultaneously.

src/Cache/Adapter/Redis.php, src/Cache/Adapter/RedisCluster.php, src/Cache/Adapter/Memcached.php, src/Cache/Adapter/Hazelcast.php — all four implement touch() with a non-atomic read-modify-write.

Important Files Changed

_{Reviews (3): Last reviewed commit: "fix: stabilize filesystem touch test" | Re-trigger Greptile}