feat(admin): add a cancel button next to the ticket process submit

Collapses the inline process form by linking back to the current list
URL without the action/id params (filters preserved).

tests/widget-system/report-ban-contract.test.cjs

@@ -184,6 +184,8 @@ test('native ban page mirrors the reference theme layout', () => {
   // 表单裸嵌 tbody 被 foster-parent 后多余行信息错位到“确认提交”下方。
   assert.match(tickets, /<tr><td colspan="6">';\s*\$this->render_ticket_process_form/)
   assert.match(tickets, /if \(\$is_processing\) \{[\s\S]*?render_ticket_process_form\(\$row, \$action_url\)[\s\S]*?\} else \{\s*\$this->render_ticket_row/)
+  // 展开的处理表单提供“取消”按钮（确认提交右侧），可收起回到列表。
+  assert.match(tickets, /process-submit.*?<\/button> <a class="button" href="' \. esc_url\(remove_query_arg\(\['action', 'id'\]\)\) . '">.*?取消/)
 
   // 分页对齐参考主题 zibpay_admin_pagenavi（每页 20 条）
   assert.match(tickets, /TICKETS_PER_PAGE = 20/)