fix(contribution-service): fix property mapping in toDto method

The toDto method was accessing non-existent properties on ContributionAccountAggregate:
- teamLevelContribution -> totalLevelPending
- teamBonusContribution -> totalBonusPending
- totalContribution -> effectiveContribution
- isCalculated -> true (always calculated when account exists)
- lastCalculatedAt -> updatedAt

This was causing "Cannot read properties of undefined (reading 'value')" error
on GET /api/v2/contribution/accounts/{accountSequence}

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

backend/services/contribution-service/src/application/queries/get-contribution-account.query.ts

@@ -169,15 +169,15 @@ export class GetContributionAccountQuery {
       message: '账户正常',
       accountSequence: account.accountSequence,
       personalContribution: account.personalContribution.value.toString(),
-      teamLevelContribution: account.teamLevelContribution.value.toString(),
-      teamBonusContribution: account.teamBonusContribution.value.toString(),
-      totalContribution: account.totalContribution.value.toString(),
+      teamLevelContribution: account.totalLevelPending.value.toString(),
+      teamBonusContribution: account.totalBonusPending.value.toString(),
+      totalContribution: account.effectiveContribution.value.toString(),
       hasAdopted: account.hasAdopted,
       directReferralAdoptedCount: account.directReferralAdoptedCount,
       unlockedLevelDepth: account.unlockedLevelDepth,
       unlockedBonusTiers: account.unlockedBonusTiers,
-      isCalculated: account.isCalculated,
-      lastCalculatedAt: account.lastCalculatedAt,
+      isCalculated: true,
+      lastCalculatedAt: account.updatedAt,
     };
   }