Standardize SurClaw ports away from defaults

- Change the API default listen port from 3000 to 3100 and include the Docker frontend origin in default CORS.

- Point Vite's default API proxy, Docker API container port, and Nginx upstream to 3100.

- Keep Docker host ports on 4002 for web, 3002 for API, and 5433 for PostgreSQL.

- Update environment examples and documentation to remove stale localhost:3000 guidance.

docker-compose.yaml

@@ -19,14 +19,14 @@ services:
     container_name: tuwen_api
     restart: unless-stopped
     environment:
-      API_PORT: 3000
+      API_PORT: 3100
       CORS_ORIGIN: http://localhost:4002,http://localhost:3001
       DATABASE_URL: postgresql://surclaw:surclaw_dev_password@db:5432/surclaw?schema=public
       SESSION_SECRET: change-me-in-production
       SESSION_COOKIE_SECURE: "false"
       FILE_STORAGE_DIR: /app/uploads
     ports:
-      - "3002:3000"
+      - "3002:3100"
     depends_on:
       - db
     volumes: