`[2026-09-22]` Failed-START alarms on 23 nh3-dev units

Failed-START alarms on 23 nh3-dev units (services/althing-notify-failure/). ⚠ Coverage is far narrower than it looks — only the 7 timer oneshots and svos.service can actually reach failed; ten daemons flap forever instead. svos.service's divergent 5-min window is LOAD-BEARING (operator ruling 2026-09-11) — do not harmonise it. Commits 1be39d1, 163bb97.