v0.5.1 — notify once per incident (no alert spam)

Fixed

• Alert spam on sustained conditions. A persistent problem (e.g. a breaching SLO) used to re-email you every throttle window — bad DX. With incident tracking on (the default), Vigilance now notifies once when the incident opens, and again only if its severity escalates or it resolves and later recurs. So a SLO that stays breached pages you once, not every 15 minutes.
• Set alerts.renotify_minutes (VIGILANCE_ALERT_RENOTIFY_MINUTES) > 0 to get a reminder every N minutes while an incident stays open (default 0 = notify once). With incidents disabled, behaviour is unchanged (one notification per throttle_minutes).

This applies to every rule (SLO burn, queue backlog, error rate, anomalies, deploy regressions, …).