fix(protocol): save DJ pay details without blocking on due-sum mismatch

Persist payment before samples to avoid consuming sample codes on validation failure, soft-delete samples on create rollback, and surface DJ due-amount mismatch as a hint only.

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

web-admin/src/views/cell-storage/protocol/ProtocolFormDialog.vue

@@ -1106,6 +1106,7 @@
     applyPayModeSwitch,
     canAddPaymentDetail,
     createPaymentDetailRow,
+    djDueAmountMismatchHint,
     evaluatePayModeSwitch,
     isPayDetailLocked,
     markPayDetailLocks,
@@ -2144,10 +2145,17 @@
   }
 
   async function handleSubmit() {
-    if (!formRef.value) return
-    await formRef.value.validate()
+    if (!formRef.value || submitLoading.value) return
+    submitLoading.value = true
+    try {
+      await formRef.value.validate()
+    } catch {
+      submitLoading.value = false
+      return
+    }
     const sampleCount = getActiveSampleCount(formData.samples)
     if (!isPayModeValidForSampleCount(formData.payMode as PresetPayMode, sampleCount)) {
+      submitLoading.value = false
       await ElMessageBox.alert(
         formData.payMode === 'djfq'
           ? '「趸交+分期」仅适用于 2 个样本，请切换缴费模式'
@@ -2162,12 +2170,18 @@
         if (!sampleRow.sampleCodeId) continue
         const sc = sampleCodeOptions.value.find((x) => x.id === sampleRow.sampleCodeId)
         if (sc?.usedInProtocol) {
+          submitLoading.value = false
           ElMessage.warning(`样本编码「${sampleRow.sampleCode || sc.sampleCode}」已被占用，请更换`)
           return
         }
       }
     }
-    submitLoading.value = true
+    if (formData.payMode === 'dj') {
+      const dueHint = djDueAmountMismatchHint(formData.contractAmount, formData.paymentDetails)
+      if (dueHint) {
+        ElMessage.warning(dueHint)
+      }
+    }
     try {
       syncFqPaymentDetailRowCount(fqPaymentContext(), formData.paymentDetails)
       const protocolAttachmentUrls = formData.attachments