优化报销审批证据布局（reimbursement-form-shared-component-migration）

client/src/pages/MobileReimbursementDetailPage.tsx

@@ -372,6 +372,7 @@ export function MobileReimbursementDetailPage() {
     mutationFn: (itemId: string) => deleteReimbursementItem(reimbursementId, itemId),
     onSuccess: async () => {
       await invalidateDetail();
+      setItemForm(null);
       setConfirmDeleteItemId("");
       toast.success("明细已删除");
     },
@@ -924,7 +925,6 @@ export function MobileReimbursementDetailPage() {
       const sourceItem = detail.items.find((candidate) => candidate.id === item.id);
       if (sourceItem) startEditItem(sourceItem);
     } : undefined,
-    onDeleteItem: canMaintainReimbursement ? (item: { id: string }) => setConfirmDeleteItemId(item.id) : undefined,
     onLinkInvoice: canMaintainReimbursement ? (invoice: { id: string }, linkedItemId: string) => linkInvoiceItemMutation.mutate({ invoiceId: invoice.id, linkedItemId }) : undefined,
     linkInvoicePending: linkInvoiceItemMutation.isPending,
     linkInvoiceErrors: invoiceItemLinkErrors,
@@ -961,7 +961,7 @@ export function MobileReimbursementDetailPage() {
               <label className="block space-y-1 text-sm text-zinc-700"><span>金额</span><Input disabled={itemSaveMutation.isPending} inputMode="decimal" value={itemForm.amount} onChange={(event) => setItemForm((current) => current ? { ...current, amount: event.target.value } : current)} /></label>
               <label className="block space-y-1 text-sm text-zinc-700"><span>说明</span><Textarea disabled={itemSaveMutation.isPending} rows={2} value={itemForm.description} onChange={(event) => setItemForm((current) => current ? { ...current, description: event.target.value } : current)} /></label>
               {shouldShowOfficeElectronicsHint(expenseTypes.find((type) => type.id === itemForm.expenseTypeId), itemForm.amount) ? <p className="text-xs text-amber-700">该金额通常应选择办公电子设备。</p> : null}
-              <div className="grid grid-cols-2 gap-2"><Button disabled={!itemForm.expenseTypeId || !itemForm.expenseDate || !Number.isFinite(Number(itemForm.amount)) || Number(itemForm.amount) <= 0 || itemSaveMutation.isPending} onClick={() => itemSaveMutation.mutate(itemForm)} type="button">保存</Button><Button disabled={itemSaveMutation.isPending} onClick={() => setItemForm(null)} type="button" variant="secondary">取消</Button></div>
+              <div className="grid grid-cols-2 gap-2"><Button disabled={!itemForm.expenseTypeId || !itemForm.expenseDate || !Number.isFinite(Number(itemForm.amount)) || Number(itemForm.amount) <= 0 || itemSaveMutation.isPending} onClick={() => itemSaveMutation.mutate(itemForm)} type="button">保存</Button><Button disabled={itemSaveMutation.isPending} onClick={() => setItemForm(null)} type="button" variant="secondary">取消</Button>{itemForm.mode === "edit" && itemForm.itemId ? <Button className="col-span-2" data-testid="reimbursement-item-delete" disabled={itemSaveMutation.isPending} onClick={() => setConfirmDeleteItemId(itemForm.itemId ?? "")} type="button" variant="destructive">删除明细</Button> : null}</div>
             </div>
           ) : <p className="text-xs text-zinc-500">选择上方动作维护明细、发票或补充附件。</p>}
         </section>