Add reference Traefik stack config for replication

Stripped-down, generic version of the Traefik Swarm setup that the
tunnel-server depends on for dynamic label-based routing. Sanitized
of infrastructure-specific details so others can replicate the setup.

Co-authored-by: Cursor <cursoragent@cursor.com>

traefik-reference.yml

@@ -0,0 +1,84 @@
+# Reference Traefik stack configuration for Docker Swarm.
+# This is NOT deployed by this project — it documents the Traefik setup
+# that the tunnel-server depends on for dynamic routing via Swarm labels.
+#
+# Key requirements:
+#   - Docker Swarm provider enabled (--providers.docker.swarmMode=true)
+#   - Exposed by default OFF (--providers.docker.exposedbydefault=false)
+#   - A shared overlay network (e.g. "traefik")
+#   - An ACME cert resolver for automatic TLS
+#   - NO file providers — all routing is done via Docker service labels
+#
+# Deploy: docker stack deploy -c traefik-reference.yml traefik
+
+networks:
+  traefik:
+    external: true
+
+services:
+  traefik-http:
+    image: traefik:v2
+    command:
+      - --providers.docker.endpoint=unix:///var/run/docker.sock
+      - --providers.docker.swarmMode=true
+      - --providers.docker.exposedbydefault=false
+      - --providers.docker.network=traefik
+      - --serverstransport.insecureskipverify=true
+      - --log.level=ERROR
+      - --global.checknewversion=false
+      - --global.sendanonymoususage=false
+      - --entrypoints.web.address=:80
+      - --entrypoints.websecure.address=:443
+      - --entrypoints.web.http.redirections.entryPoint.to=websecure
+      - --entrypoints.web.http.redirections.entryPoint.scheme=https
+      - --entrypoints.web.http.redirections.entryPoint.permanent=true
+      - --entryPoints.websecure.forwardedHeaders.insecure=true
+      - --entryPoints.websecure.transport.respondingTimeouts.idleTimeout=600s
+      - --entryPoints.websecure.transport.respondingTimeouts.readTimeout=600s
+      - --entryPoints.websecure.transport.respondingTimeouts.writeTimeout=600s
+      - --certificatesresolvers.letsencryptresolver.acme.httpchallenge=true
+      - --certificatesresolvers.letsencryptresolver.acme.httpchallenge.entrypoint=web
+      - --certificatesresolvers.letsencryptresolver.acme.email=admin@example.com
+      - --certificatesresolvers.letsencryptresolver.acme.storage=/letsencrypt/acme.json
+      - --api.dashboard=true
+    ports:
+      - target: 80
+        published: 80
+        protocol: tcp
+        mode: host
+      - target: 443
+        published: 443
+        protocol: tcp
+        mode: host
+      - target: 443
+        published: 443
+        protocol: udp
+        mode: host
+    volumes:
+      - /var/run/docker.sock:/var/run/docker.sock:ro
+      - traefik-letsencrypt:/letsencrypt
+    networks:
+      - traefik
+    deploy:
+      endpoint_mode: dnsrr
+      replicas: 1
+      placement:
+        constraints:
+          - node.role == manager
+      labels:
+        traefik.enable: "true"
+        traefik.docker.network: "traefik"
+        traefik.http.routers.traefik-dashboard.rule: "Host(`traefik.example.com`)"
+        traefik.http.routers.traefik-dashboard.entrypoints: "websecure"
+        traefik.http.routers.traefik-dashboard.tls: "true"
+        traefik.http.routers.traefik-dashboard.tls.certresolver: "letsencryptresolver"
+        traefik.http.routers.traefik-dashboard.service: "api@internal"
+        traefik.http.services.traefik-dashboard.loadbalancer.server.port: "888"
+      update_config:
+        order: stop-first
+        failure_action: rollback
+      restart_policy:
+        condition: on-failure
+
+volumes:
+  traefik-letsencrypt: