Snapshot for shared-data

[Dshadowzh]

Shared-data currently does not support backup and restore functionality. While S3 provides high availability and data persistence, backup and restore capabilities are still essential for recovering from unexpected incidents or periodical snapshot. This proposal introduces the concept of snapshots to address this need.

There are two main scenarios for using snapshots:

• Data Backup and Recovery: Snapshots can be used to back up data at specific points in time and restore from those snapshots as needed. This process can be performed manually or scheduled periodically.

• Automated Backup and Recovery: The system can automatically create snapshots of the latest data, enabling recovery from the most recent snapshot with best-effort reliability. shared-data mode support backup restore though automated snapshot #53867

Product proposal docs

https://docs.google.com/document/d/1rPG_evLRK-XG5W1p0sNk0xibEOrdMllrxMV__mCwmJs/edit?tab=t.0#heading=h.iofn2gmg8h2y

[Dshadowzh]

Detailed design doc: https://docs.google.com/document/d/1gIM1yHOpLIlwJEDkH4jfEcfukdW7B1hX7QZOap3045s/edit?tab=t.0#heading=h.1fjlx8nqi5nv