fix: capstone 12 — fix parse error + correct widget path

Parse error: 'set after column' → 'insert after' (MDL语法)
Runtime error: 'colActions' path too deep for widgetRef (3层限制)
  → 'dgMyTickets.colActions' 兼容 backend 路径解析

Author: Test

academy/zh/capstone-helpdesk/参考实现/12-integrate-actions.mdl

@@ -55,7 +55,7 @@ alter page HD.Ticket_Detail {
 -- ============================================================
 
 alter page HD.MyTickets_Overview {
-  insert after colActions {
+  insert after dgMyTickets.colActions {
     column colCopy (caption: '', ShowContentAs: customContent, ColumnWidth: manual, Size: 60) {
       actionbutton btnCopy (
         caption:     'Copy',