Covers all 16 notification types (daily reminders, state-based health/
automation alerts, real-time DNS and integration-down alerts, and the
quiet-hours digest), what triggers each, and what does and doesn't
respect quiet hours and maintenance windows. Every trigger condition
and threshold was cross-checked against the actual scheduler/monitor
code, not just the settings labels.
Also fixes the "Daily reminder time" hint text in NotificationSettings,
which had gone stale — it listed only 4 of the 6 checks that actually
share that schedule (missing domain expiry and PBS verification).
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
