# Greenhouse Sensors: runbook (question and answer style)

Created 2026-01-05. Each entry is a question a person (or an AI reader) would ask, with a tested answer: where it lives, the command, how to verify, how to undo, known traps. No secrets; say where they are. If this file and `state.md` disagree, the more detailed note wins and the other is corrected. Times are UTC.

## How do I restore from the latest backup? (since 2026-01-05)
_(what is backed up, where, the exact steps, how to verify, how long it takes, the last restore drill date)_

## How do I check that everything is healthy? (since 2026-01-05)
_(point to `verification/verification.md` and the script)_

## How do I add a new component? (since 2026-01-05)
_(steps, plus the notes to update; the matrix in `sync-tracker.md` lists them)_

## What mistakes were made and must not be repeated?
- _(format: Never X because Y happened on DATE. Instead Z. See the incident entry.)_

## How do I swap a node's batteries? (since 2026-03-12)
Open the box, swap both cells, wait for the next reading on the dashboard. See `sensor-node.md`.

## What do I do when a frost alert fires? (since 2026-03-12)
Check the heater first, then the valves. See `alerting.md` and the frost night incident.

## How do I restore last night's backup? (since 2026-03-12)
See `backup-job.md`. Last restore drill: 2026-03-11, 4 minutes. Gateway restarts: `gateway.md`.