fix(planting-service): 修复 BigInt userId 比较问题

- 使用 toString() 比较 BigInt 避免类型不匹配
- 添加调试日志帮助排查问题

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/services/planting-service/src/application/services/contract-signing.service.ts

@@ -157,7 +157,13 @@ export class ContractSigningService {
    */
   async getTask(orderNo: string, userId: bigint): Promise<ContractSigningTaskDto | null> {
     const task = await this.taskRepo.findByOrderNo(orderNo);
-    if (!task || task.userId !== userId) {
+    if (!task) {
+      this.logger.warn(`Task not found for orderNo: ${orderNo}`);
+      return null;
+    }
+    // 使用 toString() 比较以避免 BigInt 类型不匹配问题
+    if (task.userId.toString() !== userId.toString()) {
+      this.logger.warn(`User mismatch for orderNo: ${orderNo}, task.userId=${task.userId}, requestUserId=${userId}`);
       return null;
     }
     return this.toDto(task);
@@ -168,7 +174,7 @@ export class ContractSigningService {
    */
   async markScrollComplete(orderNo: string, userId: bigint): Promise<void> {
     const task = await this.taskRepo.findByOrderNo(orderNo);
-    if (!task || task.userId !== userId) {
+    if (!task || task.userId.toString() !== userId.toString()) {
       throw new Error('签署任务不存在');
     }
 
@@ -182,7 +188,7 @@ export class ContractSigningService {
    */
   async acknowledgeContract(orderNo: string, userId: bigint): Promise<void> {
     const task = await this.taskRepo.findByOrderNo(orderNo);
-    if (!task || task.userId !== userId) {
+    if (!task || task.userId.toString() !== userId.toString()) {
       throw new Error('签署任务不存在');
     }
 
@@ -201,7 +207,7 @@ export class ContractSigningService {
     params: SignContractParams,
   ): Promise<void> {
     const task = await this.taskRepo.findByOrderNo(orderNo);
-    if (!task || task.userId !== userId) {
+    if (!task || task.userId.toString() !== userId.toString()) {
       throw new Error('签署任务不存在');
     }
 
@@ -231,7 +237,7 @@ export class ContractSigningService {
     params: SignContractParams,
   ): Promise<void> {
     const task = await this.taskRepo.findByOrderNo(orderNo);
-    if (!task || task.userId !== userId) {
+    if (!task || task.userId.toString() !== userId.toString()) {
       throw new Error('签署任务不存在');
     }