Free design.md API and CLI

# Pull the public image from GitHub Container Registry.
docker pull ghcr.io/zuchka/free-design-md:latest

# Load ANTHROPIC_API_KEY into your shell or secret manager first.
docker run --rm \
  -p 3000:3000 \
  -e FREE_DESIGN_MD_SELF_HOSTED=1 \
  -e ANTHROPIC_API_KEY \
  -e DATABASE_URL=postgresql://user:password@postgres-host:5432/database \
  ghcr.io/zuchka/free-design-md:latest

After the container starts, open http://localhost:3000. The command passes the ANTHROPIC_API_KEY variable name to Docker, not the key value; if the variable is missing, self-host mode returns a setup error.

# Optional: build locally from a repository checkout.
docker build -t free-design-md:local .

Build locally only when you are developing from a checkout or need to test unreleased changes.

# Optional endpoint protection.
PROMETHEUS_METRICS_TOKEN=replace-with-a-long-random-token

# Prometheus scrape config.
scrape_configs:
  - job_name: free-design-md
    metrics_path: /api/metrics
    authorization:
      type: Bearer
      credentials: replace-with-a-long-random-token
    static_configs:
      - targets:
          - freedesign.md

When PROMETHEUS_METRICS_TOKEN is set, /api/metrics requires either an Authorization: Bearer token or an x-prometheus-token header. If you run multiple app processes, scrape each process for latency histograms. Database-backed counters and billing totals are shared; scrape one replica or deduplicate those series before aggregating.