refactor: backend port 8000 → 7000 pour eviter conflits applicatifs

- Dockerfile: EXPOSE + CMD uvicorn --port 7000
- app/config.py: PORT default 8000 → 7000
- nginx default.conf: 6x proxy_pass backend:8000 → backend:7000
- docker-compose.prod.yml: BACKEND_PORT default 8001 → 7000, internal 7000
- docker-compose.yml (dev): 8000:8000 → 7000:7000
- imago-admin/docker-compose.yml: VITE_API_BASE_URL + port mapping → 7000
- .env.example: BACKEND_PORT=8001 → 7000
- deploy.sh: defaults + invites port 8001 → 7000

docker-compose/docker-compose.yml

@@ -59,7 +59,7 @@ services:
       context: ..
       dockerfile: Dockerfile
     ports:
-      - "8000:8000"
+      - "7000:7000"
     env_file:
       - ../.env
     environment: