fix(pre-planting): 合并详情显示实际份数和金额，不再硬编码

问题：合并详情页"合并份数"显示订单条数(7)而非实际份数(10)，
"总价值"硬编码 订单数×1887，每笔订单金额也硬编码 1,887。

修复：
后端 getMergeDetail:
  - 新增 sourceOrders[] 含每笔订单的 portionCount + totalAmount
  - 新增 totalPortions（总份数）和 totalAmount（总金额）

前端 PrePlantingMerge model:
  - 新增 MergeSourceOrder 类
  - 新增 sourceOrders/totalPortions/totalAmount 字段

前端合并详情页:
  - "合并份数"用 totalPortions 替代 sourceOrderNos.length
  - "总价值"用 totalAmount 替代硬编码计算
  - 来源订单列表显示每笔实际金额和份数（多份时显示"N份"前缀）

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/services/planting-service/src/pre-planting/application/services/pre-planting-application.service.ts

@@ -397,6 +397,9 @@ export class PrePlantingApplicationService {
   ): Promise<{
     mergeNo: string;
     sourceOrderNos: string[];
+    sourceOrders: { orderNo: string; portionCount: number; totalAmount: number }[];
+    totalPortions: number;
+    totalAmount: number;
     treeCount: number;
     contractStatus: string;
     contractSignedAt: Date | null;
@@ -408,9 +411,28 @@ export class PrePlantingApplicationService {
       if (!merge || merge.userId !== userId) {
         throw new NotFoundException(`合并记录不存在: ${mergeNo}`);
       }
+
+      // 查询源订单的份数和金额
+      const orderRecords = await tx.prePlantingOrder.findMany({
+        where: { orderNo: { in: merge.sourceOrderNos } },
+        select: { orderNo: true, portionCount: true, totalAmount: true },
+        orderBy: { createdAt: 'asc' },
+      });
+
+      const sourceOrders = orderRecords.map((o) => ({
+        orderNo: o.orderNo,
+        portionCount: o.portionCount,
+        totalAmount: Number(o.totalAmount),
+      }));
+      const totalPortions = sourceOrders.reduce((sum, o) => sum + o.portionCount, 0);
+      const totalAmount = sourceOrders.reduce((sum, o) => sum + o.totalAmount, 0);
+
       return {
         mergeNo: merge.mergeNo,
         sourceOrderNos: merge.sourceOrderNos,
+        sourceOrders,
+        totalPortions,
+        totalAmount,
         treeCount: merge.treeCount,
         contractStatus: merge.contractStatus,
         contractSignedAt: merge.contractSignedAt,

frontend/mobile-app/lib/core/services/pre_planting_service.dart

@@ -165,9 +165,33 @@ class PrePlantingOrder {
 }
 
 /// 预种合并记录（5 份 → 1 棵树）
+/// 合并来源订单详情
+class MergeSourceOrder {
+  final String orderNo;
+  final int portionCount;
+  final double totalAmount;
+
+  MergeSourceOrder({
+    required this.orderNo,
+    required this.portionCount,
+    required this.totalAmount,
+  });
+
+  factory MergeSourceOrder.fromJson(Map<String, dynamic> json) {
+    return MergeSourceOrder(
+      orderNo: json['orderNo'] ?? '',
+      portionCount: json['portionCount'] ?? 1,
+      totalAmount: (json['totalAmount'] ?? 0).toDouble(),
+    );
+  }
+}
+
 class PrePlantingMerge {
   final String mergeNo;
-  final List<String> sourceOrderNos;  // 5 笔来源订单号
+  final List<String> sourceOrderNos;  // 来源订单号列表
+  final List<MergeSourceOrder> sourceOrders; // 来源订单详情（含份数和金额）
+  final int totalPortions;            // 合并总份数（应为 10）
+  final double totalAmount;           // 合并总金额（各订单实际支付之和）
   final int treeCount;                // 合并产生的树数（固定 1）
   final PrePlantingContractStatus contractStatus;
   final DateTime? contractSignedAt;
@@ -179,6 +203,9 @@ class PrePlantingMerge {
   PrePlantingMerge({
     required this.mergeNo,
     required this.sourceOrderNos,
+    this.sourceOrders = const [],
+    this.totalPortions = 0,
+    this.totalAmount = 0,
     required this.treeCount,
     required this.contractStatus,
     this.contractSignedAt,
@@ -195,12 +222,19 @@ class PrePlantingMerge {
   bool get isMiningEnabled => miningEnabledAt != null;
 
   factory PrePlantingMerge.fromJson(Map<String, dynamic> json) {
+    final sourceOrders = (json['sourceOrders'] as List<dynamic>?)
+            ?.map((e) => MergeSourceOrder.fromJson(e as Map<String, dynamic>))
+            .toList() ??
+        [];
     return PrePlantingMerge(
       mergeNo: json['mergeNo'] ?? '',
       sourceOrderNos: (json['sourceOrderNos'] as List<dynamic>?)
               ?.map((e) => e.toString())
               .toList() ??
           [],
+      sourceOrders: sourceOrders,
+      totalPortions: json['totalPortions'] ?? sourceOrders.fold(0, (sum, o) => sum + o.portionCount),
+      totalAmount: (json['totalAmount'] ?? sourceOrders.fold(0.0, (sum, o) => sum + o.totalAmount)).toDouble(),
       treeCount: json['treeCount'] ?? 1,
       contractStatus: _parseContractStatus(json['contractStatus']),
       contractSignedAt: json['contractSignedAt'] != null

frontend/mobile-app/lib/features/pre_planting/presentation/pages/pre_planting_merge_detail_page.dart

@@ -320,11 +320,11 @@ class _PrePlantingMergeDetailPageState
           // 信息行
           _buildDetailRow('合并时间', _formatDateTime(merge.mergedAt)),
           const SizedBox(height: 8),
-          _buildDetailRow('合并份数', '${merge.sourceOrderNos.length} 份 → 1 棵树'),
+          _buildDetailRow('合并份数', '${merge.totalPortions > 0 ? merge.totalPortions : merge.sourceOrderNos.length} 份 → 1 棵树'),
           const SizedBox(height: 8),
           _buildDetailRow(
             '总价值',
-            '${(merge.sourceOrderNos.length * 1887).toString()} 绿积分',
+            '${merge.totalAmount > 0 ? _formatNumber(merge.totalAmount) : _formatNumber(merge.sourceOrderNos.length * 1887.0)} 绿积分',
           ),
           if (merge.selectedProvince != null) ...[
             const SizedBox(height: 8),
@@ -458,7 +458,7 @@ class _PrePlantingMergeDetailPageState
         crossAxisAlignment: CrossAxisAlignment.start,
         children: [
           Text(
-            '来源订单（${merge.sourceOrderNos.length} 笔）',
+            '来源订单（${merge.sourceOrderNos.length} 笔，共 ${merge.totalPortions > 0 ? merge.totalPortions : merge.sourceOrderNos.length} 份）',
             style: const TextStyle(
               fontSize: 16,
               fontFamily: 'Inter',
@@ -467,6 +467,60 @@ class _PrePlantingMergeDetailPageState
             ),
           ),
           const SizedBox(height: 12),
+          // 优先使用 sourceOrders（含份数和金额），降级用 sourceOrderNos
+          if (merge.sourceOrders.isNotEmpty)
+            ...merge.sourceOrders.asMap().entries.map((entry) {
+              final index = entry.key;
+              final order = entry.value;
+              return Padding(
+                padding: EdgeInsets.only(
+                  bottom: index < merge.sourceOrders.length - 1 ? 8 : 0,
+                ),
+                child: Row(
+                  children: [
+                    Container(
+                      width: 24,
+                      height: 24,
+                      decoration: BoxDecoration(
+                        color:
+                            const Color(0xFFD4AF37).withValues(alpha: 0.15),
+                        borderRadius: BorderRadius.circular(12),
+                      ),
+                      child: Center(
+                        child: Text(
+                          '${index + 1}',
+                          style: const TextStyle(
+                            fontSize: 12,
+                            fontWeight: FontWeight.w600,
+                            color: Color(0xFFD4AF37),
+                          ),
+                        ),
+                      ),
+                    ),
+                    const SizedBox(width: 8),
+                    Expanded(
+                      child: Text(
+                        order.orderNo,
+                        style: const TextStyle(
+                          fontSize: 14,
+                          fontFamily: 'Inter',
+                          color: Color(0xFF5D4037),
+                        ),
+                        overflow: TextOverflow.ellipsis,
+                      ),
+                    ),
+                    Text(
+                      '${order.portionCount > 1 ? "${order.portionCount}份 " : ""}${_formatNumber(order.totalAmount)} 绿积分',
+                      style: const TextStyle(
+                        fontSize: 13,
+                        color: Color(0xFF745D43),
+                      ),
+                    ),
+                  ],
+                ),
+              );
+            })
+          else
             ...merge.sourceOrderNos.asMap().entries.map((entry) {
               final index = entry.key;
               final orderNo = entry.value;
@@ -507,13 +561,6 @@ class _PrePlantingMergeDetailPageState
                         overflow: TextOverflow.ellipsis,
                       ),
                     ),
-                  const Text(
-                    '1,887 绿积分',
-                    style: TextStyle(
-                      fontSize: 13,
-                      color: Color(0xFF745D43),
-                    ),
-                  ),
                   ],
                 ),
               );
@@ -650,6 +697,20 @@ class _PrePlantingMergeDetailPageState
     );
   }
 
+  /// 格式化金额（整数不带小数点，带千分位）
+  String _formatNumber(double value) {
+    if (value == value.truncateToDouble()) {
+      return value.toInt().toString().replaceAllMapped(
+            RegExp(r'(\d)(?=(\d{3})+(?!\d))'),
+            (m) => '${m[1]},',
+          );
+    }
+    return value.toStringAsFixed(2).replaceAllMapped(
+          RegExp(r'(\d)(?=(\d{3})+(?!\d))'),
+          (m) => '${m[1]},',
+        );
+  }
+
   /// 格式化日期时间
   String _formatDateTime(DateTime dt) {
     return '${dt.year}-${dt.month.toString().padLeft(2, '0')}-'