添加Docker自包含部署分支

- 新增 Seg_Server_Docker 自包含部署内容，包含前后端、FastAPI、Celery、PostgreSQL、Redis、MinIO、演示视频和 DICOM 数据。

- 保留 demo 数据以支持恢复演示出厂设置，排除 SAM 2.1 .pt 权重并在 README 中补充下载命令。

- 补充 GPU 部署、backend/worker 镜像复用、frpc/frps + NPM 公网域名反代部署说明。

- 在 .env/.env.example 中用 # XXXX 标注局域网和公网域名部署需要修改的配置项。

- 添加部署分支 .gitignore，忽略本地模型权重、构建产物、缓存和日志。

backend/progress_events.py

@@ -0,0 +1,66 @@
+"""Progress event payloads and Redis publication helpers."""
+
+from __future__ import annotations
+
+import json
+import logging
+from datetime import datetime, timezone
+from typing import Any
+
+from redis_client import get_redis_client
+from statuses import TASK_STATUS_CANCELLED, TASK_STATUS_FAILED, TASK_STATUS_SUCCESS
+
+logger = logging.getLogger(__name__)
+
+PROGRESS_CHANNEL = "seg:progress"
+
+
+def _iso_now() -> str:
+    return datetime.now(timezone.utc).isoformat()
+
+
+def _event_type(task_status: str) -> str:
+    if task_status == TASK_STATUS_SUCCESS:
+        return "complete"
+    if task_status == TASK_STATUS_CANCELLED:
+        return "cancelled"
+    if task_status == TASK_STATUS_FAILED:
+        return "error"
+    return "progress"
+
+
+def task_progress_payload(task: Any) -> dict[str, Any]:
+    """Build the WebSocket payload from a persisted processing task."""
+    project = getattr(task, "project", None)
+    project_name = getattr(project, "name", None)
+    status = getattr(task, "status", "")
+    updated_at = getattr(task, "updated_at", None)
+    timestamp = updated_at.isoformat() if updated_at is not None else _iso_now()
+    message = getattr(task, "message", None)
+
+    return {
+        "type": _event_type(status),
+        "taskId": f"task-{task.id}",
+        "task_id": task.id,
+        "project_id": getattr(task, "project_id", None),
+        "projectName": project_name,
+        "filename": project_name,
+        "progress": getattr(task, "progress", 0),
+        "status": message or status,
+        "message": message,
+        "error": getattr(task, "error", None),
+        "timestamp": timestamp,
+    }
+
+
+def publish_progress_event(payload: dict[str, Any]) -> None:
+    """Publish a JSON progress event without failing the worker on Redis errors."""
+    try:
+        get_redis_client().publish(PROGRESS_CHANNEL, json.dumps(payload, ensure_ascii=False))
+    except Exception as exc:  # noqa: BLE001
+        logger.warning("Failed to publish progress event: %s", exc)
+
+
+def publish_task_progress_event(task: Any) -> None:
+    """Publish a progress event for a ProcessingTask ORM object."""
+    publish_progress_event(task_progress_payload(task))