feat(pre-planting): 合并后走正常签合同流程，购买第5份直接跳合并详情页

- pre_planting_service: CreatePrePlantingOrderResponse 增加 merged/mergeNo 字段
- pre_planting_purchase_page: 购买成功若触发合并，直接跳转合并详情签合同
- contract_check_service: 注入 PrePlantingService，checkAll 增加预种待签合并检查
- pending_contracts_page: 同时展示普通合同和预种合并待签卡片，复用现有签合同弹窗流程
- injection_container: contractCheckServiceProvider 注入 prePlantingService

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

frontend/mobile-app/lib/core/di/injection_container.dart

@@ -166,10 +166,14 @@ final contractSigningServiceProvider = Provider<ContractSigningService>((ref) {
   return ContractSigningService(apiClient: apiClient);
 });
 
-// Contract Check Service Provider (用于启动时检查未签署合同)
+// Contract Check Service Provider (用于启动时检查未签署合同，含预种待签合并)
 final contractCheckServiceProvider = Provider<ContractCheckService>((ref) {
   final contractSigningService = ref.watch(contractSigningServiceProvider);
-  return ContractCheckService(contractSigningService: contractSigningService);
+  final prePlantingService = ref.watch(prePlantingServiceProvider);
+  return ContractCheckService(
+    contractSigningService: contractSigningService,
+    prePlantingService: prePlantingService,
+  );
 });
 
 // KYC Service Provider (调用 identity-service)

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

@@ -1,5 +1,6 @@
 import 'package:flutter/foundation.dart';
 import 'contract_signing_service.dart';
+import 'pre_planting_service.dart';
 
 /// 合同检查结果
 class ContractCheckResult {
@@ -15,11 +16,15 @@ class ContractCheckResult {
   /// 已付款但未完成 KYC 的订单数量
   final int paidOrderCount;
 
+  /// 待签署的预种合并合同编号（有则跳到合并详情页）
+  final String? pendingPrePlantingMergeNo;
+
   ContractCheckResult({
     required this.hasPendingContracts,
     required this.requiresKyc,
     this.kycMessage,
     this.paidOrderCount = 0,
+    this.pendingPrePlantingMergeNo,
   });
 
   /// 是否需要强制操作（有待签署合同或需要 KYC）
@@ -30,21 +35,23 @@ class ContractCheckResult {
 /// 用于在 App 启动时检查用户是否有未签署的合同或需要完成 KYC
 class ContractCheckService {
   final ContractSigningService _contractSigningService;
+  final PrePlantingService _prePlantingService;
 
   ContractCheckService({
     required ContractSigningService contractSigningService,
-  }) : _contractSigningService = contractSigningService;
+    required PrePlantingService prePlantingService,
+  })  : _contractSigningService = contractSigningService,
+        _prePlantingService = prePlantingService;
 
-  /// 检查是否有待签署的合同
+  /// 检查是否有待签署的合同（含预种合并合同）
   /// 返回 true 表示有待签署合同，需要强制签署
   Future<bool> hasPendingContracts() async {
     try {
-      // 获取未签署任务（包括待签署和超时未签署的）
       final unsignedTasks = await _contractSigningService.getUnsignedTasks();
-      return unsignedTasks.isNotEmpty;
+      if (unsignedTasks.isNotEmpty) return true;
+      final mergeNo = await _getPendingPrePlantingMergeNo();
+      return mergeNo != null;
     } catch (e) {
-      // debugPrint('[ContractCheckService] 检查待签署合同失败: $e');
-      // 检查失败时不阻止用户使用 App
       return false;
     }
   }
@@ -52,23 +59,29 @@ class ContractCheckService {
   /// 综合检查：待签署合同和 KYC 需求
   ///
   /// 返回检查结果，包含：
-  /// - 是否有待签署的合同
+  /// - 是否有待签署的合同（含预种合并合同）
   /// - 是否需要先完成 KYC（有已付款订单但未完成 KYC）
   Future<ContractCheckResult> checkAll() async {
     try {
-      // 1. 检查未签署的合同
+      // 1. 检查普通认种未签署合同
       final unsignedTasks = await _contractSigningService.getUnsignedTasks();
-      final hasPending = unsignedTasks.isNotEmpty;
+      if (unsignedTasks.isNotEmpty) {
-
-      // 2. 如果有待签署的合同，直接返回（不需要再检查 KYC）
-      if (hasPending) {
-        // debugPrint('[ContractCheckService] 检测到 ${unsignedTasks.length} 个待签署合同');
         return ContractCheckResult(
           hasPendingContracts: true,
           requiresKyc: false,
         );
       }
 
+      // 2. 检查预种待签合并合同
+      final pendingMergeNo = await _getPendingPrePlantingMergeNo();
+      if (pendingMergeNo != null) {
+        return ContractCheckResult(
+          hasPendingContracts: true,
+          requiresKyc: false,
+          pendingPrePlantingMergeNo: pendingMergeNo,
+        );
+      }
+
       // 3. 没有待签署合同，检查是否有需要 KYC 的情况
       final kycResult = await _contractSigningService.checkKycRequirement();
 
@@ -79,8 +92,6 @@ class ContractCheckService {
         paidOrderCount: kycResult.paidOrderCount,
       );
     } catch (e) {
-      // debugPrint('[ContractCheckService] 综合检查失败: $e');
-      // 检查失败时不阻止用户使用 App
       return ContractCheckResult(
         hasPendingContracts: false,
         requiresKyc: false,
@@ -92,10 +103,24 @@ class ContractCheckService {
   Future<int> getPendingContractCount() async {
     try {
       final unsignedTasks = await _contractSigningService.getUnsignedTasks();
-      return unsignedTasks.length;
+      if (unsignedTasks.isNotEmpty) return unsignedTasks.length;
+      final mergeNo = await _getPendingPrePlantingMergeNo();
+      return mergeNo != null ? 1 : 0;
     } catch (e) {
-      // debugPrint('[ContractCheckService] 获取待签署合同数量失败: $e');
       return 0;
     }
   }
+
+  /// 查找第一个待签署的预种合并合同编号
+  Future<String?> _getPendingPrePlantingMergeNo() async {
+    try {
+      final merges = await _prePlantingService.getMerges();
+      final pending = merges.where(
+        (m) => m.contractStatus == PrePlantingContractStatus.pending,
+      );
+      return pending.isEmpty ? null : pending.first.mergeNo;
+    } catch (e) {
+      return null;
+    }
+  }
 }

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

@@ -230,12 +230,16 @@ class CreatePrePlantingOrderResponse {
   final int portionCount;
   final double totalAmount;
   final double pricePerPortion;
+  final bool merged;
+  final String? mergeNo;
 
   CreatePrePlantingOrderResponse({
     required this.orderNo,
     required this.portionCount,
     required this.totalAmount,
     required this.pricePerPortion,
+    this.merged = false,
+    this.mergeNo,
   });
 
   factory CreatePrePlantingOrderResponse.fromJson(Map<String, dynamic> json) {
@@ -244,6 +248,8 @@ class CreatePrePlantingOrderResponse {
       portionCount: json['portionCount'] ?? 1,
       totalAmount: (json['totalAmount'] ?? 3566).toDouble(),
       pricePerPortion: (json['pricePerPortion'] ?? 3566).toDouble(),
+      merged: json['merged'] == true,
+      mergeNo: json['mergeNo']?.toString(),
     );
   }
 }

frontend/mobile-app/lib/features/contract_signing/presentation/pages/pending_contracts_page.dart

@@ -3,10 +3,12 @@ import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:go_router/go_router.dart';
 import '../../../../core/di/injection_container.dart';
 import '../../../../core/services/contract_signing_service.dart';
+import '../../../../core/services/pre_planting_service.dart';
 import '../../../../routes/route_paths.dart';
 
 /// 待签署合同列表页面
 /// 用于 App 启动时检查并强制用户签署未完成的合同
+/// 包含：普通认种合同 + 预种合并合同
 class PendingContractsPage extends ConsumerStatefulWidget {
   /// 是否为强制模式（不允许跳过）
   final bool forceSign;
@@ -22,6 +24,7 @@ class PendingContractsPage extends ConsumerStatefulWidget {
 
 class _PendingContractsPageState extends ConsumerState<PendingContractsPage> {
   List<ContractSigningTask> _unsignedTasks = [];
+  List<PrePlantingMerge> _pendingMerges = [];
   bool _isLoading = true;
   String? _errorMessage;
 
@@ -38,18 +41,29 @@ class _PendingContractsPageState extends ConsumerState<PendingContractsPage> {
     });
 
     try {
-      final service = ref.read(contractSigningServiceProvider);
+      final contractService = ref.read(contractSigningServiceProvider);
+      final prePlantingService = ref.read(prePlantingServiceProvider);
 
-      // 获取所有未签署任务（包括待签署和超时未签署）
+      // 并行加载：普通认种未签合同 + 预种待签合并
-      final tasks = await service.getUnsignedTasks();
+      final results = await Future.wait([
+        contractService.getUnsignedTasks(),
+        prePlantingService.getMerges(),
+      ]);
+
+      final tasks = results[0] as List<ContractSigningTask>;
+      final allMerges = results[1] as List<PrePlantingMerge>;
+      final pendingMerges = allMerges
+          .where((m) => m.contractStatus == PrePlantingContractStatus.pending)
+          .toList();
 
       setState(() {
         _unsignedTasks = tasks;
+        _pendingMerges = pendingMerges;
         _isLoading = false;
       });
 
-      // 如果没有待签署任务，自动返回
+      // 如果没有任何待签署任务，自动返回
-      if (_unsignedTasks.isEmpty) {
+      if (_unsignedTasks.isEmpty && _pendingMerges.isEmpty) {
         if (mounted) {
           context.pop(true);
         }
@@ -62,7 +76,7 @@ class _PendingContractsPageState extends ConsumerState<PendingContractsPage> {
     }
   }
 
-  /// 签署合同
+  /// 签署普通认种合同
   Future<void> _signContract(ContractSigningTask task) async {
     final result = await context.push<bool>(
       '${RoutePaths.contractSigning}/${task.orderNo}',
@@ -74,6 +88,13 @@ class _PendingContractsPageState extends ConsumerState<PendingContractsPage> {
     }
   }
 
+  /// 签署预种合并合同（跳转到合并详情页）
+  Future<void> _signPrePlantingMerge(PrePlantingMerge merge) async {
+    await context.push('${RoutePaths.prePlantingMergeDetail}/${merge.mergeNo}');
+    // 返回后刷新，合并可能已签署
+    _loadTasks();
+  }
+
   /// 跳过（仅非强制模式）
   void _skip() {
     if (!widget.forceSign) {
@@ -177,7 +198,7 @@ class _PendingContractsPageState extends ConsumerState<PendingContractsPage> {
       );
     }
 
-    if (_unsignedTasks.isEmpty) {
+    if (_unsignedTasks.isEmpty && _pendingMerges.isEmpty) {
       return const Center(
         child: Column(
           mainAxisAlignment: MainAxisAlignment.center,
@@ -200,10 +221,12 @@ class _PendingContractsPageState extends ConsumerState<PendingContractsPage> {
     return RefreshIndicator(
       onRefresh: _loadTasks,
       color: const Color(0xFFD4AF37),
-      child: ListView.builder(
+      child: ListView(
         padding: const EdgeInsets.all(16),
-        itemCount: _unsignedTasks.length,
+        children: [
-        itemBuilder: (context, index) => _buildTaskCard(_unsignedTasks[index]),
+          ..._unsignedTasks.map((task) => _buildTaskCard(task)),
+          ..._pendingMerges.map((merge) => _buildMergeCard(merge)),
+        ],
       ),
     );
   }
@@ -289,95 +312,34 @@ class _PendingContractsPageState extends ConsumerState<PendingContractsPage> {
                 ],
               ),
               const SizedBox(height: 12),
-              // 状态提示
               if (isTimeout)
-                Container(
+                _buildStatusHint(
-                  padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
+                  color: const Color(0xFFFFEBEE),
-                  decoration: BoxDecoration(
+                  icon: Icons.warning_amber_rounded,
-                    color: const Color(0xFFFFEBEE),
+                  iconColor: const Color(0xFFE53935),
-                    borderRadius: BorderRadius.circular(8),
+                  text: '签署已超时，请尽快补签',
-                  ),
+                  textColor: const Color(0xFFE53935),
-                  child: const Row(
-                    children: [
-                      Icon(Icons.warning_amber_rounded, color: Color(0xFFE53935), size: 16),
-                      SizedBox(width: 8),
-                      Expanded(
-                        child: Text(
-                          '签署已超时，请尽快补签',
-                          style: TextStyle(
-                            fontSize: 12,
-                            color: Color(0xFFE53935),
-                          ),
-                        ),
-                      ),
-                    ],
-                  ),
                 )
               else if (isUrgent)
-                Container(
+                _buildStatusHint(
-                  padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
+                  color: const Color(0xFFFFF3E0),
-                  decoration: BoxDecoration(
+                  icon: Icons.access_time,
-                    color: const Color(0xFFFFF3E0),
+                  iconColor: const Color(0xFFFF9800),
-                    borderRadius: BorderRadius.circular(8),
+                  text: '剩余 ${_formatRemainingTime(task.remainingSeconds)}',
-                  ),
+                  textColor: const Color(0xFFE65100),
-                  child: Row(
-                    children: [
-                      const Icon(Icons.access_time, color: Color(0xFFFF9800), size: 16),
-                      const SizedBox(width: 8),
-                      Expanded(
-                        child: Text(
-                          '剩余 ${_formatRemainingTime(task.remainingSeconds)}',
-                          style: const TextStyle(
-                            fontSize: 12,
-                            color: Color(0xFFE65100),
-                          ),
-                        ),
-                      ),
-                    ],
-                  ),
                 )
               else
-                Container(
+                _buildStatusHint(
-                  padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
+                  color: const Color(0xFFE3F2FD),
-                  decoration: BoxDecoration(
+                  icon: Icons.timer,
-                    color: const Color(0xFFE3F2FD),
+                  iconColor: const Color(0xFF1976D2),
-                    borderRadius: BorderRadius.circular(8),
+                  text: '剩余 ${_formatRemainingTime(task.remainingSeconds)}',
-                  ),
+                  textColor: const Color(0xFF1976D2),
-                  child: Row(
-                    children: [
-                      const Icon(Icons.timer, color: Color(0xFF1976D2), size: 16),
-                      const SizedBox(width: 8),
-                      Expanded(
-                        child: Text(
-                          '剩余 ${_formatRemainingTime(task.remainingSeconds)}',
-                          style: const TextStyle(
-                            fontSize: 12,
-                            color: Color(0xFF1976D2),
-                          ),
-                        ),
-                      ),
-                    ],
-                  ),
                 ),
               const SizedBox(height: 12),
-              // 签署按钮
+              _buildSignButton(
-              Container(
+                label: isTimeout ? '立即补签' : '立即签署',
-                width: double.infinity,
+                color: isTimeout ? const Color(0xFFE53935) : const Color(0xFFD4AF37),
-                height: 44,
-                decoration: BoxDecoration(
-                  color: isTimeout ? const Color(0xFFE53935) : const Color(0xFFD4AF37),
-                  borderRadius: BorderRadius.circular(8),
-                ),
-                child: Center(
-                  child: Text(
-                    isTimeout ? '立即补签' : '立即签署',
-                    style: const TextStyle(
-                      fontSize: 16,
-                      fontWeight: FontWeight.w600,
-                      color: Colors.white,
-                    ),
-                  ),
-                ),
               ),
             ],
           ),
@@ -386,6 +348,142 @@ class _PendingContractsPageState extends ConsumerState<PendingContractsPage> {
     );
   }
 
+  /// 预种合并待签卡片
+  Widget _buildMergeCard(PrePlantingMerge merge) {
+    return Container(
+      margin: const EdgeInsets.only(bottom: 16),
+      decoration: BoxDecoration(
+        color: Colors.white,
+        borderRadius: BorderRadius.circular(12),
+        boxShadow: [
+          BoxShadow(
+            color: Colors.black.withValues(alpha: 0.1),
+            blurRadius: 10,
+            offset: const Offset(0, 4),
+          ),
+        ],
+        border: Border.all(color: const Color(0xFF4CAF50), width: 1),
+      ),
+      child: InkWell(
+        onTap: () => _signPrePlantingMerge(merge),
+        borderRadius: BorderRadius.circular(12),
+        child: Padding(
+          padding: const EdgeInsets.all(16),
+          child: Column(
+            crossAxisAlignment: CrossAxisAlignment.start,
+            children: [
+              Row(
+                mainAxisAlignment: MainAxisAlignment.spaceBetween,
+                children: [
+                  Expanded(
+                    child: Column(
+                      crossAxisAlignment: CrossAxisAlignment.start,
+                      children: [
+                        Text(
+                          '合并编号: ${merge.mergeNo}',
+                          style: const TextStyle(
+                            fontSize: 14,
+                            color: Color(0xFF666666),
+                          ),
+                        ),
+                        const SizedBox(height: 4),
+                        Text(
+                          '${merge.treeCount} 棵预种合并树',
+                          style: const TextStyle(
+                            fontSize: 18,
+                            fontWeight: FontWeight.bold,
+                            color: Color(0xFF5D4037),
+                          ),
+                        ),
+                      ],
+                    ),
+                  ),
+                  Container(
+                    padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 6),
+                    decoration: BoxDecoration(
+                      color: const Color(0xFFE8F5E9),
+                      borderRadius: BorderRadius.circular(20),
+                    ),
+                    child: const Text(
+                      '待签署',
+                      style: TextStyle(
+                        fontSize: 12,
+                        fontWeight: FontWeight.w600,
+                        color: Color(0xFF2E7D32),
+                      ),
+                    ),
+                  ),
+                ],
+              ),
+              const SizedBox(height: 12),
+              _buildStatusHint(
+                color: const Color(0xFFE8F5E9),
+                icon: Icons.park_outlined,
+                iconColor: const Color(0xFF4CAF50),
+                text: '5 份预种份额已合并，请签署合同以开启挖矿',
+                textColor: const Color(0xFF2E7D32),
+              ),
+              const SizedBox(height: 12),
+              _buildSignButton(
+                label: '立即签署',
+                color: const Color(0xFF4CAF50),
+              ),
+            ],
+          ),
+        ),
+      ),
+    );
+  }
+
+  Widget _buildStatusHint({
+    required Color color,
+    required IconData icon,
+    required Color iconColor,
+    required String text,
+    required Color textColor,
+  }) {
+    return Container(
+      padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
+      decoration: BoxDecoration(
+        color: color,
+        borderRadius: BorderRadius.circular(8),
+      ),
+      child: Row(
+        children: [
+          Icon(icon, color: iconColor, size: 16),
+          const SizedBox(width: 8),
+          Expanded(
+            child: Text(
+              text,
+              style: TextStyle(fontSize: 12, color: textColor),
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+
+  Widget _buildSignButton({required String label, required Color color}) {
+    return Container(
+      width: double.infinity,
+      height: 44,
+      decoration: BoxDecoration(
+        color: color,
+        borderRadius: BorderRadius.circular(8),
+      ),
+      child: Center(
+        child: Text(
+          label,
+          style: const TextStyle(
+            fontSize: 16,
+            fontWeight: FontWeight.w600,
+            color: Colors.white,
+          ),
+        ),
+      ),
+    );
+  }
+
   Widget _buildStatusBadge(ContractSigningTask task) {
     Color bgColor;
     Color textColor;

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

@@ -368,7 +368,8 @@ class _PrePlantingPurchasePageState
 
       debugPrint(
         '[PrePlantingPurchase] 购买成功: orderNo=${response.orderNo}, '
-        'portions=${response.portionCount}, total=${response.totalAmount}',
+        'portions=${response.portionCount}, total=${response.totalAmount}, '
+        'merged=${response.merged}, mergeNo=${response.mergeNo}',
       );
 
       if (mounted) {
@@ -382,8 +383,13 @@ class _PrePlantingPurchasePageState
           ),
         );
 
-        // 返回上一页（Profile 页面会自动刷新）
+        // 如果触发了合并（5 份凑满 1 棵树），直接跳转到合并详情页签合同
-        context.pop(true);
+        if (response.merged && response.mergeNo != null) {
+          context.push('${RoutePaths.prePlantingMergeDetail}/${response.mergeNo}');
+        } else {
+          // 返回上一页（Profile 页面会自动刷新）
+          context.pop(true);
+        }
       }
     } catch (e, stack) {
       debugPrint('[PrePlantingPurchase] ★ 购买失败 type=${e.runtimeType}: $e');