[Feature Request]: Keep latest loaded rules if update fails instead of fallback.

[cerwio]

Please confirm:

• I have searched existing feature requests (open and closed) and found no duplicates.

Problem Statement

Currently if the periodic rules update interval fails the extension falls back to the default 1.2.0 rules which is causing false alerts, the extension should keep the last downloaded rules if that happens.

The lookup can fail due to a GitHub outage or rate limit, or just a general network issue and then the extension immediately falls back.

Benefits for MSPs

This reduces false alerts as well as keeps the user protected with the latest known rules instead of the outdated default ones.

Value or Importance

Fairly important to eliminate the risk of a flood of alerts.