Make Iceberg snapshot expiration configurable in TableCoordinator

[Gezi-lzq]

Background

In TableCoordinator, snapshot expiration is currently set with fixed parameters: snapshots older than 1 hour are expired and only the latest snapshot is retained. This behavior is not configurable by users and may not be suitable for all operational scenarios.

Proposal

Expose the following configuration options via LogConfig:

• table.topic.expire.snapshot.enabled (default: true): Enable/disable automatic snapshot expiration
• table.topic.expire.snapshot.older.than.hours (default: 1): Set retention duration (in hours)
• table.topic.expire.snapshot.retain.last (default: 1): Minimum snapshots to retain

Providing these options would allow users to adjust snapshot expiration policies according to their workload and requirements.