fix(contribution): 确保 HEADQUARTERS 账户存在后再更新算力

修复 Record to update not found 错误，在调用 addContribution 前
先调用 ensureSystemAccountsExist 确保系统账户记录已创建。

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

backend/services/contribution-service/src/application/services/contribution-calculation.service.ts

@@ -285,6 +285,8 @@ export class ContributionCalculationService {
         (sum, u) => sum.add(u.amount),
         new ContributionAmount(0),
       );
+      // 确保 HEADQUARTERS 账户存在
+      await this.systemAccountRepository.ensureSystemAccountsExist();
       await this.systemAccountRepository.addContribution('HEADQUARTERS', totalUnallocatedAmount);
 
       // 发布 HEADQUARTERS 账户同步事件