When a user's direct referral count reaches 2 or 4, the system now automatically
backfills previously pending TEAM_BONUS (T2/T3) contributions that were allocated
to headquarters while waiting for unlock conditions.
- Add BonusClaimService for handling bonus backfill logic
- Add findPendingBonusByAccountSequence and claimBonusRecords to repository
- Integrate bonus claim into updateReferrerUnlockStatus flow
- Add BonusClaimed event consumer in mining-wallet-service
- Generate ledger records for backfilled contributions
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>