Sibling to the weekly summary, focused on critical alerts only. Pings
Slack daily while any critical alerts are open; skips the post entirely
when zero, so no daily "all clear" noise.
- Daily 08:00 UTC cron + `workflow_dispatch` with `severity` input
(default `critical`, override to `high`/`medium`/`low` for manual
checks)
- Reuses the existing `dependabot-summary` environment (token, channel,
bot)
- Alerts link at the end is severity-filtered
nicktrn
18d7144e74