* test(s3/lifecycle): cover reader cursor + Run validation contracts
Layer 2 tests pinning four reader-package contracts the dispatcher
pipeline depends on: MinTsNs anchors at frozen positions, Snapshot
returns a deep copy in both directions, Restore replaces (not merges),
and Run validates ShardID/Events/BucketsPath before subscribing.
* test(s3/lifecycle): tighten cursor composition assertions
Snapshot deep-copy: also assert cursor doesn't see keys added to the
returned map. Restore replace: freeze before second Restore and assert
IsFrozen returns false after, pinning the contract that Restore wipes
frozen state alongside the value map. Run validation: bound the call
with a 5s context timeout so a regression that lets Run reach the nil
client surfaces as a failure instead of a hang.