refactor(docker): remove traefik compose, cleanup deploy folder

- Delete docker-compose.traefik.yml (redundant overlay)
- Remove Traefik service from docker-compose.prod.yml
- Add traefik external network and labels to api/web services in prod compose
- Add TRAEFIK_ENTRYPOINT env var to all Traefik router labels
- Remove deploy/ folder (portainer-stack.yml, .env examples, README)

Production compose now assumes external Traefik proxy on Docker network.
All environment variables come from host environment only.

docker-compose.traefik.yml

@@ -1,27 +0,0 @@
-services:
-  api:
-    networks:
-      - default
-      - traefik
-    labels:
-      - "traefik.enable=true"
-      - "traefik.http.routers.headquarter-api.rule=Host(`api.${ROOT_DOMAIN}`)"
-      - "traefik.http.routers.headquarter-api.entrypoints=${TRAEFIK_ENTRYPOINT:-websecure}"
-      - "traefik.http.routers.headquarter-api.tls.certresolver=${TRAEFIK_CERT_RESOLVER:-letsencrypt}"
-      - "traefik.http.services.headquarter-api.loadbalancer.server.port=8000"
-
-  web:
-    networks:
-      - default
-      - traefik
-    labels:
-      - "traefik.enable=true"
-      - "traefik.http.routers.headquarter-web.rule=Host(`${ROOT_DOMAIN}`)"
-      - "traefik.http.routers.headquarter-web.entrypoints=${TRAEFIK_ENTRYPOINT:-websecure}"
-      - "traefik.http.routers.headquarter-web.tls.certresolver=${TRAEFIK_CERT_RESOLVER:-letsencrypt}"
-      - "traefik.http.services.headquarter-web.loadbalancer.server.port=80"
-
-networks:
-  traefik:
-    name: ${TRAEFIK_NETWORK:-traefik}
-    external: true