feat: unify execution and add workspace file imports

Remove Ask/Execute modes and general product tool approvals so requests use the selected runtime, enabled capabilities, and execution account permissions. Migrate retired application metadata while preserving user content.

Retire the Results page while retaining conversation images and stored artifacts. Add local and remote workspace file imports, timestamps and sorting, improve image discovery and saving, and refine workspace navigation and supervision responsiveness. Include the accompanying web-search changes, tests, probes, and product documentation.

Remote imports require an updated Agent. Existing artifacts are not automatically copied into project directories. Validation evidence and outstanding failures remain documented in feature progress files; no full test suite or real-model calls were rerun for this commit.

Release note: Run requests without switching work modes, import files into a selected local or remote workspace folder, sort workspace files by date, and keep using conversation images after removal of the Results page.

docs/features/document-processing/implementation.md

@@ -5,7 +5,9 @@
 
 ## 解析与设置
 
-`DocumentParsingService` 统一服务聊天文档、知识库、成果导入和设置测试。`HttpDocumentOcr`
+`DocumentParsingService` 统一服务聊天文档、知识库、旧成果导入 API 和设置测试。成果导入界面
+已移除；工作区“导入文件”只复制或上传原件，不解析、不自动加入消息。会话附件仍由下述会话
+资产存储管理，不自动复制到项目目录。`HttpDocumentOcr`
 在 Main 调用 PaddleOCR-VL，`render-ocr-pdf.ts` 使用 PDF.js 和本机 Canvas 渲染选中页，
 不需要本地 OCR 权重。来源未配置时继续原有本地行为；产品没有测试地址默认值。
 
@@ -66,6 +68,9 @@ Main 先保存资产，再保存草稿或接受队列；消息、分支建立独
 会话删除、项目删除及清空数据均核对引用，启动回收已无归属的记录和孤立 UUID 目录。
 清理失败保留无引用数据库记录供下次重试，不回滚已接受的草稿。
 
+Renderer 仅在活动会话 ID 非空时读取附件草稿；切换到尚无会话的消息通道项目时不发出
+`context:get-draft` 请求。切回本地会话后照常恢复附件，Main 继续校验会话 ID 的 UUID 格式。
+
 引用保存按输入顺序去重并查询资产。已有引用的顺序、会话归属均相同，且资产无需从临时目录
 转存时，直接返回，不重复开启写事务或删除、插入引用。空引用同样适用；顺序、归属或附件
 发生变化时仍按原事务更新，临时资产仍须转存。