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/memory/prd.md

@@ -462,8 +462,8 @@ Project 记忆与 Global 偏好冲突时：
 5. Embedding 只能发送用户已配置允许的记忆，Restricted 默认不发送外部服务。
 6. 记忆内容和来源不出现在普通日志与通知。
 7. 跨分区晋升需要明确操作和审计。
-8. Ask 和 Execute 使用同一只读记忆检索边界。
-9. 记忆不能绕过系统指令、工具审批和工作区权限。
+8. 普通请求使用同一只读记忆检索边界，不依赖产品工作模式。
+9. 记忆不能绕过系统指令、能力范围和工作区权限。
 
 ## 18. 实施顺序