Function update 

pub fn update(state: &RouterStateInner)

Recomputes run-focused metric families from the authoritative projection.

Update behavior is deterministic for each scrape:

• Recounts all run states from ReplayReducer::run_instances().
• Overwrites actionqueue_runs_total{state=...} gauge samples.
• Overwrites aggregate gauges actionqueue_runs_ready and actionqueue_runs_running.
• Observes scheduling lag histogram samples for lag-eligible states only.