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/continuous-learning/prd.md

@@ -43,7 +43,7 @@ Observe
 2. 新候选默认 `candidate`，通过离线评估后先进入 `shadow`。
 3. 第一阶段只允许人工晋升。
 4. 每次晋升必须记录 Baseline、候选、评估结果、作用域和回滚版本。
-5. 学习不能修改安全边界、工具审批、目录权限、沙箱或 Electron 配置。
+5. 学习不能修改能力分配、目录权限、沙箱或 Electron 配置。
 6. 失败案例和用户负反馈只作为评估数据，不直接成为新规则。
 7. 回放案例必须脱敏、版本化，并得到用户明确选择或来自仓库公开样例。
 8. 模型评估不是唯一真值，优先使用确定性验收和人工反馈。