feat: 平台治理与对象存储增强，审批中心与运行日志整合

- 新增 storage/policy.py 落盘策略：按大小/类型决定文件存 MinIO 或内联数据库
- 数据处理源文件与生成结果写入 MinIO 并登记 storage_objects，支持失败回滚
- 算力节点训练产物按版本归档到 MinIO，登记 model_artifacts
- 数据转换任务输入输出对象化，支持从 MinIO 读写
- 新增审批中心（申请/我的/策略）、组织与权限、运行日志整合页面
- schema 与 docker 配置、前端路由侧边栏、治理文档同步更新

Co-Authored-By: Claude <noreply@anthropic.com>

backend/app/modules/storage/minio_store.py

@@ -3,6 +3,7 @@ from __future__ import annotations
 from datetime import timedelta
 from functools import lru_cache
 from io import BytesIO
+from collections.abc import Iterator
 from typing import Any
 
 from minio import Minio
@@ -53,6 +54,64 @@ class MinioObjectStorage:
         except S3Error as exc:
             raise ObjectStorageError(str(exc)) from exc
 
+    def get_bytes(self, object_key: str) -> bytes:
+        """Read an object through the backend for small API responses and workers."""
+        self._ensure_enabled()
+        self.ensure_bucket()
+        response = None
+        try:
+            response = self.client.get_object(self.bucket, object_key)
+            return response.read()
+        except S3Error as exc:
+            raise ObjectStorageError(str(exc)) from exc
+        finally:
+            if response is not None:
+                response.close()
+                response.release_conn()
+
+    def iter_bytes(self, object_key: str, chunk_size: int = 256 * 1024) -> Iterator[bytes]:
+        """Stream an object without loading the complete file into memory."""
+        self._ensure_enabled()
+        self.ensure_bucket()
+        response = None
+        try:
+            response = self.client.get_object(self.bucket, object_key)
+            while True:
+                chunk = response.read(chunk_size)
+                if not chunk:
+                    break
+                yield chunk
+        except S3Error as exc:
+            raise ObjectStorageError(str(exc)) from exc
+        finally:
+            if response is not None:
+                response.close()
+                response.release_conn()
+
+    def list_objects(self, prefix: str) -> list[dict[str, Any]]:
+        self._ensure_enabled()
+        self.ensure_bucket()
+        try:
+            return [
+                {
+                    "object_key": item.object_name,
+                    "byte_size": item.size or 0,
+                    "etag": item.etag,
+                    "last_modified": item.last_modified.isoformat() if item.last_modified else None,
+                }
+                for item in self.client.list_objects(self.bucket, prefix=prefix, recursive=True)
+            ]
+        except S3Error as exc:
+            raise ObjectStorageError(str(exc)) from exc
+
+    def delete(self, object_key: str) -> None:
+        self._ensure_enabled()
+        self.ensure_bucket()
+        try:
+            self.client.remove_object(self.bucket, object_key)
+        except S3Error as exc:
+            raise ObjectStorageError(str(exc)) from exc
+
     def put_bytes(self, object_key: str, content: bytes, content_type: str = "application/octet-stream") -> dict[str, Any]:
         self._ensure_enabled()
         self.ensure_bucket()