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.

sites/index.html

@@ -461,12 +461,8 @@
                 </svg>
               </div>
               <span class="feature-number">04</span>
-              <h3>区分问答与执行</h3>
-              <p>Ask 保持只读；Execute 按当前账号权限执行操作，并记录工具调用。可用工具随所选 Runtime 和配置变化。</p>
-              <div class="mode-row" aria-label="两种工作模式">
-                <span>Ask <small>只读</small></span>
-                <span class="is-accent">Execute <small>按账号权限执行</small></span>
-              </div>
+              <h3>直接提问或交付任务</h3>
+              <p>无需切换工作模式。可用工具由所选 Runtime 和已启用能力决定，操作使用当前账号权限，工具调用保留在运行记录中。</p>
             </article>
 
             <article class="feature-card">