feat(tasks): implement atomic claims and leases

backend-api/internal/transport/webui/templates/task-detail.gohtml

@@ -76,26 +76,40 @@
     {{if .Task.CanCancel}}
     <noscript>
       <section class="noscript-cancel" aria-labelledby="noscript-cancel-heading">
+        {{if .Task.CancelRequiresAck}}
+        <h2 id="noscript-cancel-heading">请求安全停止任务</h2>
+        <p>设备确认安全停止前，任务仍保持当前执行状态。</p>
+        {{else}}
         <h2 id="noscript-cancel-heading">确认取消任务</h2>
         <p>取消后任务不会自动恢复。</p>
+        {{end}}
         <form method="post" action="/tasks/{{pathPart .Task.ID}}/cancel">
           <input type="hidden" name="csrf_token" value="{{.CSRFToken}}">
           <input type="hidden" name="cancel_key" value="{{.CancelKey}}">
-          <button class="button danger" type="submit">确认取消</button>
+          <button class="button danger" type="submit">
+            {{if .Task.CancelRequiresAck}}确认请求停止{{else}}确认取消{{end}}
+          </button>
         </form>
       </section>
     </noscript>
 
     <dialog class="confirm-dialog" data-cancel-dialog aria-labelledby="cancel-title">
+      {{if .Task.CancelRequiresAck}}
+      <h2 id="cancel-title">请求安全停止任务？</h2>
+      <p>系统将通知采购 App 在安全检查点停止；设备确认前任务仍保持当前执行状态。</p>
+      {{else}}
       <h2 id="cancel-title">确认取消任务？</h2>
       <p>任务取消后不会自动恢复，采购执行员将不能再领取。</p>
+      {{end}}
       <div class="dialog-actions">
         <button class="button" type="button" data-keep-task>保留任务</button>
         <form method="post" action="/tasks/{{pathPart .Task.ID}}/cancel" data-submit-form>
           <input type="hidden" name="csrf_token" value="{{.CSRFToken}}">
           <input type="hidden" name="cancel_key" value="{{.CancelKey}}">
           <button class="button danger" type="submit" data-submit-button
-            data-loading-label="正在取消…">确认取消</button>
+            data-loading-label="{{if .Task.CancelRequiresAck}}正在请求停止…{{else}}正在取消…{{end}}">
+            {{if .Task.CancelRequiresAck}}确认请求停止{{else}}确认取消{{end}}
+          </button>
         </form>
       </div>
     </dialog>