Service up

Machine-readable check: GET /health (JSON). This page is the API root, not the SPA.

Operator handbook: the repository docs/ folder includes index.html (serve locally with npx serve docs) for admin API & integrations (FCM, mailbox, SMTP, geolocation, third-party token rate limits, traffic information / Google Routes, Google Calendar), PDM PDF parsers, feedback triage, and maintenance windows. Markdown summaries: docs/ADMIN_INTEGRATIONS.md, docs/API.md. OpenAPI: backend/src/docs/*.yaml merged for /docs, /openapi.json, /openapi.yaml when API docs are enabled.