update: remove local fs

docker-compose.yml

@@ -25,6 +25,7 @@ services:
       dockerfile: backend/Dockerfile
     restart: unless-stopped
     # No host port: architecture §2.2 — only Nginx is externally reachable.
+    # No local-FS volume: backend stores everything in RustFS (RUSTFS_*).
     environment:
       DATABASE_URL: mysql+asyncmy://${MYSQL_USER:-model_platform}:${MYSQL_PASSWORD:-model_platform}@mysql:3306/${MYSQL_DATABASE:-model_platform}?charset=utf8mb4
       JWT_SECRET: ${JWT_SECRET:-local-jwt-secret}
@@ -32,9 +33,7 @@ services:
       RUSTFS_ENDPOINT: ${RUSTFS_ENDPOINT:-http://rustfs:9000}
       RUSTFS_ACCESS_KEY: ${RUSTFS_ACCESS_KEY:-modelplatform}
       RUSTFS_SECRET_KEY: ${RUSTFS_SECRET_KEY:-modelplatformsecret}
-      WORKSPACE_ROOT: /workspace/workspaces
     volumes:
-      - ./deploy/data/workspaces:/workspace/workspaces
       - ./backend:/app/backend:ro
       - ./common:/app/common:ro
     depends_on: