Update the application to use port 3000 across all services

Adjusts port configurations from 5000 to 3000 in .replit, Dockerfile, docker-compose.yml, replit.md and server/index.ts for consistent service deployment.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: dec54137-d5a2-4406-8ad4-5f2f9fb110bf
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/0715008c-7244-40f4-befc-26c014852236/5d315300-98fa-429a-abb0-4fdce6a2e3c9.jpg

docker-compose.yml

@@ -38,7 +38,7 @@ services:
     pull_policy: never
     environment:
       NODE_ENV: production
-      PORT: 5000
+      PORT: 3000
       DATABASE_URL: postgresql://regisflow:${POSTGRES_PASSWORD:-RegisFlow2024!PostgreSQL}@regisflow-db:5432/regisflow
       SESSION_SECRET: ${SESSION_SECRET:-RegisFlow2024SessionSecretKey1234567890ABCDEF}
       TZ: ${TZ:-Europe/Paris}
@@ -50,10 +50,10 @@ services:
       - backup_data:/app/backups
       - logs_data:/app/logs
     ports:
-      - "5000:5000"
+      - "3000:3000"
     restart: unless-stopped
     healthcheck:
-      test: ["CMD-SHELL", "wget --no-verbose --tries=1 --spider http://localhost:5000/ || exit 1"]
+      test: ["CMD-SHELL", "wget --no-verbose --tries=1 --spider http://localhost:3000/ || exit 1"]
       interval: 30s
       timeout: 10s
       retries: 5