feat(admin): open ticket creation in a dialog on the list page

Move "代客提交工单" back into a native <dialog> on the ticket list while
the ticket workspace stays a full page. Closing asks before discarding
input, ignores backdrop clicks, resets the form and returns focus; an
uncertain create result keeps the form locked behind "重新加载".

Remove the ?view=new create page route and its styles.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

assets/js/admin-tickets.js

@@ -1,4 +1,4 @@
-/** 工单后台：列表 / 处理工作区 / 代客提交均为页内视图；写操作只使用工单 REST 接口，成功后整页跳转刷新。 */
+/** 工单后台：列表与处理工作区为页内视图，代客提交为列表页上的原生 dialog；写操作只使用工单 REST 接口，成功后整页跳转刷新。 */
 (function () {
   'use strict';
 
@@ -7,6 +7,8 @@
   if (!root || !config) return;
 
   var strings = config.strings;
+  var dialog = document.getElementById('aksrt-ticket-create-dialog');
+  var opener = null;
   var feedbackBox = root.querySelector('[data-aksrt-ticket-feedback]');
   var detail = root.querySelector('[data-aksrt-ticket-detail]');
   var ticketId = detail ? parseInt(detail.dataset.aksrtTicketDetail, 10) : 0;
@@ -133,7 +135,6 @@
   /** 成功后跳回工作区并带结果码；未提交的其它表单草稿暂存到 sessionStorage，加载后恢复。 */
   function go(id, kind, remaining) {
     var url = new URL(window.location.href);
-    url.searchParams.delete('view');
     url.searchParams.set('id', String(id));
     url.searchParams.set('aksrt_ticket_msg', kind);
     url.hash = '';
@@ -176,12 +177,50 @@
     }
   }
 
+  /** 关闭代客提交弹窗：保存中不可关；有未保存输入时先确认。不响应遮罩点击，避免误关丢失输入。 */
+  function closeDialog() {
+    if (saving || !dialog.open) return;
+    if (!stale && Object.keys(drafts()).length && !window.confirm(strings.discard)) return;
+    dialog.close();
+  }
+
+  if (dialog) {
+    dialog.addEventListener('cancel', function (event) {
+      event.preventDefault();
+      closeDialog();
+    });
+    dialog.addEventListener('close', function () {
+      var form = dialog.querySelector('[data-aksrt-ticket-form]');
+      if (form && !stale) {
+        form.reset();
+        baselines.set(form, values(form));
+        form.querySelectorAll('[name]').forEach(validateText);
+        form.querySelectorAll('[data-aksrt-ticket-editor]').forEach(counter);
+        feedback('', false, false);
+      }
+      if (opener && opener.isConnected) opener.focus();
+    });
+  }
+
   root.addEventListener('click', function (event) {
     if (event.target.closest('[data-aksrt-ticket-reload]')) {
       leaving = true;
       window.location.reload();
       return;
     }
+    if (dialog && event.target.closest('[data-aksrt-dialog-close]')) {
+      closeDialog();
+      return;
+    }
+    var open = dialog && event.target.closest('[data-aksrt-dialog-open="' + dialog.id + '"]');
+    if (open) {
+      if (saving) return;
+      opener = open;
+      // 结果未确认时保留「重新加载」提示，重新打开也不能再提交。
+      if (!stale) feedback('', false, false);
+      dialog.showModal();
+      return;
+    }
     if (saving || stale) return;
     var assign = event.target.closest('[data-aksrt-ticket-assign]');
     if (assign) {