Add Uptime Kuma uptime monitor

[riccjohn]

Summary

Add Uptime Kuma as a lightweight uptime monitor and status page.

Changes

• docker-compose.yml — add uptime-kuma service (image: louislam/uptime-kuma:2, Traefik labels for uptime-kuma.woggles.work)
• homepage/config/services.yaml — add Monitoring section with Uptime Kuma card + uptimekuma widget (no API key required)
• scripts/setup.sh — add mkdir -p uptime-kuma/data
• .env.example — no changes needed

Post-deploy steps

1. Visit https://uptime-kuma.woggles.work
2. Create a status page with slug home
3. Confirm the homepage widget populates

Acceptance

• ./scripts/lint-config.sh exits 0
• Uptime Kuma is reachable at https://uptime-kuma.woggles.work
• Homepage widget shows status data