Incident and maintenance lifecycle

Observer treats incidents and maintenances as instances of the same underlying row (the updates table). The lifecycle state is derived from a grid of timestamp columns rather than an explicit state column; this keeps the model coherent regardless of whether the transition happened via API, server action, or cron.

States

State	Trigger
`draft`	Row exists but `published_at IS NULL`. Invisible to the public.
`published`	`published_at` set. Renders on the public page.
`resolved`	`resolved_at` set. Final lifecycle for an incident.
`scheduled`	Maintenance with `scheduled_start_at` set, `actual_start_at NULL`.
`in_progress`	Maintenance with `actual_start_at` set, `actual_end_at NULL`.
`completed`	Maintenance with `actual_end_at` set.
`canceled`	Either type with `canceled_at` set.
`deleted`	Soft-delete via `deleted_at`. Permanent; not displayed anywhere.

Transitions

       draft
         │ POST /publish
         ▼
     published ──── POST /resolve ──▶ resolved
         │
         │ DELETE
         ▼
       deleted

  (maintenance only)
   scheduled ── cron @ scheduled_start_at ──▶ in_progress
                                                    │ cron @ scheduled_end_at
                                                    ▼
                                                 completed

   any state ── POST /cancel ──▶ canceled

Webhook events

Each transition fires a webhook event. See Webhook payload reference for exact body shapes.

Event	Fires when
`incident.created`	Row inserted (regardless of draft / publish).
`incident.published`	`published_at` set.
`incident.updated`	Title, severity, or affected services patched.
`incident.message_added`	Message appended to timeline.
`incident.resolved`	`resolved_at` set.
`incident.deleted`	`deleted_at` set.
`maintenance.scheduled`	Row inserted with `scheduled_start_at`.
`maintenance.starting_soon`	Cron fires within 1h of `scheduled_start_at`. Once per row.
`maintenance.started`	`actual_start_at` set (manual or cron).
`maintenance.completed`	`actual_end_at` set.
`maintenance.canceled`	`canceled_at` set.

Auto-message side effects

Some lifecycle transitions append a system message to the timeline:

maintenance.started (cron or API) appends an Information message: "Maintenance started."
maintenance.completed (cron or API) appends a Resolved message: "Maintenance completed."
maintenance.canceled (API) appends an Information message: "Maintenance canceled."

These are visible on the public page exactly like operator-authored messages. They exist so the timeline reflects every state change without requiring the operator to remember.