docs: add Traefik docker-compose example to expose the store over a domain

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

README.md

@@ -39,6 +39,50 @@ docker run -d --name gadfly-reports -p 8090:8090 -v gadfly-reports-data:/data \
   gitea.stevedudenhoeffer.com/steve/gadfly-reports:latest
 ```
 
+### Deploy behind Traefik (expose over a domain)
+
+```yaml
+# docker-compose.yml — publish gadfly-reports at https://reports.example.com via Traefik.
+services:
+  gadfly-reports:
+    image: gitea.stevedudenhoeffer.com/steve/gadfly-reports:latest
+    restart: unless-stopped
+    environment:
+      # Auth is built in: callers (gadfly emit, gadfly-mcp) send this as a bearer
+      # token; /healthz stays open. ADDR and DB default to :8090 and
+      # /data/gadfly-reports.db inside the image.
+      GADFLY_REPORTS_TOKEN: ${GADFLY_REPORTS_TOKEN:?set GADFLY_REPORTS_TOKEN in .env}
+    volumes:
+      - gadfly-reports-data:/data
+    networks: [traefik]
+    healthcheck:
+      test: ["CMD", "wget", "-q", "-O", "-", "http://localhost:8090/healthz"]
+      interval: 30s
+      timeout: 5s
+      retries: 3
+    labels:
+      - "traefik.enable=true"
+      - "traefik.http.routers.gadfly-reports.rule=Host(`reports.example.com`)"
+      - "traefik.http.routers.gadfly-reports.entrypoints=websecure"
+      - "traefik.http.routers.gadfly-reports.tls=true"
+      - "traefik.http.routers.gadfly-reports.tls.certresolver=letsencrypt"
+      - "traefik.http.services.gadfly-reports.loadbalancer.server.port=8090"
+
+volumes:
+  gadfly-reports-data:
+
+networks:
+  traefik:
+    external: true   # the network your Traefik instance is attached to
+```
+
+Put `GADFLY_REPORTS_TOKEN=<secret>` in a `.env` beside the compose file. Tailor the three
+Traefik bits to your setup — the **host** (`reports.example.com`), the **entrypoint**
+(`websecure`) and the **certresolver** (`letsencrypt`) must match your Traefik config, and the
+`traefik` network must be the external one Traefik watches. Traefik terminates TLS and forwards
+to the container's `:8090`. Then point `gadfly`'s `GADFLY_FINDINGS_URL` and `gadfly-mcp`'s
+`--store` at `https://reports.example.com` (with the same token).
+
 ## HTTP API (the canonical contract)
 
 | Method & path | Body / query | Purpose |