[deploy] Docker Compose: charon + prometheus + grafana stack for Hetzner CX22

[obchain]

Context

One command (docker compose up -d) should bring up the whole stack on a fresh VPS. Target host is a €3.79/mo Hetzner CX22 (2 vCPU, 4 GB RAM, 40 GB SSD) — tight, but enough for one-chain v0.1.

Scope

• Multi-stage Dockerfile for charon (builder + slim runtime image)
• docker-compose.yml with three services: charon, prometheus, grafana
• Prometheus config scraping charon:9090
• Grafana with a pre-provisioned dashboard (liquidations, profit, scan latency, chain health gauges)
• Volumes for Prometheus/Grafana persistence
• .env-driven secrets (mounted into the charon container)
• Runbook in deploy/README.md: provision VPS, clone repo, docker compose up -d

Acceptance criteria

• docker compose up -d on a fresh Ubuntu 22.04 box brings all three services up
• Grafana reachable at :3000 with the default dashboard populated
• Charon container restarts on crash (restart policy)
• Built image < 200 MB (scratch or distroless base)
• Runbook is copy-paste-able end-to-end for a beginner

References

• PRD section 7b (Docker Deployment)

[obchain]

Superseded — Docker Compose stack shipped in feat/27-docker-compose.