Feature Request: Redis-like Automatic BGSAVE / Snapshot Support in Microsoft Garnet

### Feature request type

### Is your feature request related to a problem? Please describe

Currently, Microsoft Garnet supports persistence through CHECKPOINT commands and incremental snapshots. However, unlike Redis, Garnet does not provide a built-in mechanism to automatically trigger snapshots based on time intervals or write activity.

In Redis, administrators can configure automatic background snapshots using the save configuration (which internally triggers BGSAVE), for example:

save 900 1
save 300 10
save 60 1000

It would be very helpful if Garnet provided a similar automatic snapshot option in the server configuration, allowing checkpoints to run periodically (for example every few minutes). This would simplify deployment and reduce operational overhead when using snapshot-based persistence without AOF.

A configuration option for automatic checkpoint scheduling would make Garnet easier to manage and closer to Redis operational behavior.

### Describe the solution you'd like

In Redis, administrators can configure automatic background snapshots using the save configuration (which internally triggers BGSAVE), for example:

save 900 1
save 300 10
save 60 1000

It would be very helpful if Garnet provided a similar automatic snapshot option in the server configuration, allowing checkpoints to run periodically (for example every few minutes). This would simplify deployment and reduce operational overhead when using snapshot-based persistence without AOF.

A configuration option for automatic checkpoint scheduling would make Garnet easier to manage and closer to Redis operational behavior.

### Describe alternatives you've considered

_No response_

### Additional context

_No response_

Start by tracing the existing CHECKPOINT commands and incremental snapshot behavior, then inspect how server configuration is defined and consumed. The work is done when Garnet has a documented configuration for automatic checkpoints based on elapsed time or write activity, with behavior comparable to the requested Redis save examples.

Written by the indexing model from the issue text.