fix: capstone 12-integrate-actions.mdl parse error — set after column → insert after

'set after column colActions' is not supported by MDL parser.
ALTER PAGE uses 'insert after colActions' syntax (lines 15, 40 use
this correctly). Only line 58 had the wrong syntax.

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 {
-  set after column colActions {
+  insert after colActions {
     column colCopy (caption: '', ShowContentAs: customContent, ColumnWidth: manual, Size: 60) {
       actionbutton btnCopy (
         caption:     'Copy',