Public status page + incident tracker

Build a public status page for a SaaS.

Core features:
1. Component list with current status (operational, degraded, down)
2. Incident timeline with markdown updates
3. Scheduled maintenance windows
4. Uptime chart (last 90 days)
5. Email/webhook subscribers on incident post

Data: components, incidents, updates, subscribers.
Must-haves: RSS/Atom feed, cached public read, admin-only writes.