[datalayer] Handle state loss on restart

[Mohammad-nassar10]

Problem Statement

The in-memory DataStore resets to zero on restart, losing all accumulated state (running request counters, latency histograms, etc.). Any extractor that builds up state over time is affected.

Proposed Solution

Options to explore

• Persist a snapshot to a ConfigMap or file on shutdown, reload on start
• Add a warm-up period where the selector treats the store as unreliable
• Replace in-memory store with a persistent backend (Redis, etc.)

Alternatives Considered

No response

Willingness to Contribute

Yes, I can submit a PR

Additional Context

Related to #42

[Mohammad-nassar10]

/assign