🐛 修复账单预览翻页重置手动选择模式

bms-front/src/views/ar/bill/components/GenerateBillDialog.vue

@@ -318,21 +318,23 @@ function queryGeneratePreview() {
     const query = buildGenerateQuery()
     resetPreview()
     previewQuery.value = query
-    fetchPreview()
+    fetchPreview(true)
   })
 }
 
-function fetchPreview() {
+function fetchPreview(initializeSelectionMode = false) {
   previewLoading.value = true
   previewArBill(buildPreviewQuery()).then(res => {
     syncingPageSelection = true
     previewRows.value = res.rows || []
     previewTotal.value = Number(res.total) || 0
     previewTotalAmount.value = Number(res.totalAmount) || 0
-    // 查询到可生成订单后默认采用“全选查询结果”模式；如需排除订单，再通过排除入口维护。
-    selectionMode.value = previewTotal.value > 0
-      ? AR_BILL_SELECTION_MODE.ALL_MATCHED
-      : AR_BILL_SELECTION_MODE.EXPLICIT
+    // 仅首次查询默认全选；翻页请求保留用户当前的选择模式。
+    if (initializeSelectionMode) {
+      selectionMode.value = previewTotal.value > 0
+        ? AR_BILL_SELECTION_MODE.ALL_MATCHED
+        : AR_BILL_SELECTION_MODE.EXPLICIT
+    }
     previewSearched.value = true
     nextTick(syncPageSelection)
   }).finally(() => {