Model Deployment auto-scaling does not work

## Summary

Model Deployment auto-scaling does not work for certain users in v25.19.0.

## Symptoms

- Affected model deployments have no metrics data in Redis
- Manager logs show: `AUTOSCALE(e:{}, rule:{}): skipping - no endpoint statistics`

## Expected Behavior

- Redis should contain endpoint metrics data
- Sokovan scheduler should apply auto-scaling rules based on metrics

## Unknown

- Why only certain users are affected
- Root cause of missing metrics in Redis

JIRA Issue: BA-3879