fix: block select-all and header filters while excel copy is on

Co-authored-by: Cursor <cursoragent@cursor.com>

web-admin/src/components/business/list-table/index.vue

@@ -274,11 +274,14 @@
     const header = target.closest('th')
     const cell = target.closest('td')
     if (header) {
-      const columns = copyableColumns()
-      const index = columns.findIndex((col) => header.classList.contains(col.id))
-      if (index < 0) return
       event.preventDefault()
       event.stopPropagation()
+      const columns = copyableColumns()
+      const index = columns.findIndex((col) => header.classList.contains(col.id))
+      if (index < 0) {
+        keepCopyFocus()
+        return
+      }
       const result = toggleAxis(selectedCols.value, index, event.shiftKey, colAnchor)
       selectedCols.value = result.selected
       colAnchor = result.anchor