[Request] Rule gaps

[nkhristinin]

Description

We introducing new feature to show Gaps for single rule

Gaps actions like - fill gap, fill remaining gaps

For all rule, we show it on monitoring tab - like how many rules have gaps,
and unfilled interval

Background & resources

• PRs: [Detection Engine] [Alerting] [Response Ops] Rule gaps kibana#206313
• Issues/metas: https://github.com/elastic/security-team/issues/8558
• Point of contact: @nkhristinin @approksiu
• Test environments: https://elastic.slack.com/archives/C071E7FCR1A/p1737044341833789

Which documentation set does this change impact?

ESS and serverless

ESS release

in 8.18

Serverless release

when docs are ready

Feature differences

API docs impact

There are internal API, should we include them?

Prerequisites, privileges, feature flags

Feature flag: storeGapsInEventLogEnabled

[nastasha-solomon]

Docs merged!