feat(m8): P1 MinIO 对象存储与文件管理

- 迁移 000023 gateway.file_objects(personal/system 归属隔离 + 部分索引)
- internal/platform/storage:minio-go 适配(端点 scheme 剥离、流式 PutObject/Open/Delete)
- internal/workbench/files.go:FileService(sha256 校验、PutObject-then-insert 回滚、delete 先删行再删对象)
- admin /api/v1/admin/files + portal /api/v1/portal/files 处理器(流式上传下载、Content-Disposition)
- RBAC file:read/file:manage;菜单加文件管理 + 门户文件仓库
- compose 增 minio 服务(S3_* anchor、不暴露端口);nginx client_max_body_size 32m→256m
- 管理端文件管理页 + 门户个人文件仓;集成测试 TestFileObjectLifecycle 连真 MinIO 通过
- healthz object_storage:true;README/PRODUCTION/进展文档同步

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

internal/identity/http.go

@@ -377,6 +377,9 @@ func adminMenus(account Account) []map[string]any {
 	if HasPermission(account, PermissionApplicationRead) || HasPermission(account, PermissionApplicationManage) {
 		assetsChildren = append(assetsChildren, map[string]any{"name": "Applications", "path": "applications", "component": "/gateway/applications", "meta": map[string]any{"title": "AI 应用"}})
 	}
+	if HasPermission(account, PermissionFileRead) || HasPermission(account, PermissionFileManage) {
+		assetsChildren = append(assetsChildren, map[string]any{"name": "Files", "path": "files", "component": "/gateway/files", "meta": map[string]any{"title": "文件管理"}})
+	}
 	if len(assetsChildren) > 0 {
 		menus = append(menus, map[string]any{"name": "Assets", "path": "/assets", "component": "/index/index", "meta": map[string]any{"title": "AI 资产", "icon": "ri:box-3-line"}, "children": assetsChildren})
 	}
@@ -424,6 +427,7 @@ func portalMenus() []map[string]any {
 			{"name": "PortalPrompts", "path": "prompts", "component": "/portal/prompts", "meta": map[string]any{"title": "Prompt 广场"}},
 			{"name": "PortalUsage", "path": "usage", "component": "/portal/usage", "meta": map[string]any{"title": "我的用量"}},
 			{"name": "PortalAccess", "path": "access", "component": "/portal/access", "meta": map[string]any{"title": "模型权限"}},
+			{"name": "PortalFiles", "path": "files", "component": "/portal/files", "meta": map[string]any{"title": "文件仓库"}},
 		}},
 	}
 }