feat(enakgame): game sessions, rewards, vouchers, budgets and events

EnakGame phases 1-8 of docs/tasks-enakgame.md (EG-101 to EG-803), built on the
existing EnakPoint/EnakCoin wallet (docs/rfc-enakgame.md).

Foundation (phase 1)
- Migrations 000103-000106: games extended with organization, slug, status,
  entry cost and result rules, old games archived (not deleted); budgets,
  versioned reward configs, sessions and session rewards; the ledger types
  GAME_SPEND_REFUND, GAME_REWARD and REWARD_REDEEM_REFUND; audit_logs.
- AuditLogger writes in the caller's transaction only.
- enakgame.limit.user_daily and global_daily organization settings.

Games and sessions (phases 2-4)
- Admin /marketing/enakgame: games, reward config versions (immutable but for
  status, one ACTIVE per game), budgets with non-overlapping global periods and
  a daily job opening the next month.
- Customer /customer/enakgame: start (Idempotency-Key, entry cost and config
  frozen on the session), complete (result validation, reward engine, max_reward
  cap, daily limits via game_reward_counters, one GAME_REWARD per budget),
  automatic refunds for system errors and deactivated games, and a session job.
- Reward engine: FIXED, SCORE_BASED, OUTCOME_BASED, PROBABILITY (crypto/rand),
  rounded down.

Vouchers and budgets (phases 5-6)
- Migration 000108 and 000107: vouchers, codes, redemptions, cost attribution;
  Economy Guard counters.
- STATIC and CODE_POOL redemption in one transaction with the REDEEM PIN action;
  realized cost traced through the lots to the budget that paid the reward.
- Budget metrics: realized cost, forecast, exposure and status. Migrations
  000109-000110 add the wallet_lots indexes they need, built CONCURRENTLY.

Events (phase 7)
- Migration 000111: game events, each with its own EVENT budget. Event extras
  stack per PRD §16 defaults, with event and per-customer limits.

External vouchers (phase 8)
- VoucherProvider contract, two-step PENDING redemption and a recovery job,
  tested with a fake provider. No provider adapter is registered yet, so
  EXTERNAL vouchers stay out of the catalog.

Not yet decided before release: reward rounding, event stacking, budget
exhaustion policy and thresholds (RFC §19.2). Migrations 000103-000111 have
not been run on any shared database.

Also fixes a leftover PAYMENT filter in a wallet test and a data race in a
test PIN fake.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/processor/wallet_processor.go

@@ -149,6 +149,38 @@ func (p *WalletProcessor) FindTransaction(ctx context.Context, idempotencyKey st
 	return p.repo.GetTransactionByIdempotencyKey(ctx, idempotencyKey)
 }
 
+// RefundLots turns the allocations of a debit back into lots for its refund
+// (docs/rfc-enakgame.md §6.3): one per lot the debit drew from, pointing back at it,
+// expiring when that lot did but at least seven days from now (RefundExpiry).
+func (p *WalletProcessor) RefundLots(ctx context.Context, debitTransactionID uuid.UUID) ([]WalletLotInput, error) {
+	allocations, err := p.repo.ListAllocationsByTransaction(ctx, debitTransactionID)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read the debit's allocations: %w", err)
+	}
+	ids := make([]uuid.UUID, 0, len(allocations))
+	for _, a := range allocations {
+		ids = append(ids, a.LotID)
+	}
+	lots, err := p.repo.GetLotsByIDs(ctx, ids)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read the debit's lots: %w", err)
+	}
+	expiries := make(map[uuid.UUID]*time.Time, len(lots))
+	for _, lot := range lots {
+		expiries[lot.ID] = lot.ExpiresAt
+	}
+	out := make([]WalletLotInput, 0, len(allocations))
+	for _, a := range allocations {
+		expiresAt, ok := expiries[a.LotID]
+		if !ok {
+			return nil, fmt.Errorf("lot %s of the debit is missing", a.LotID)
+		}
+		lotID := a.LotID
+		out = append(out, WalletLotInput{Amount: a.Amount, ExpiresAt: RefundExpiry(expiresAt, p.now()), OriginLotID: &lotID})
+	}
+	return out, nil
+}
+
 // ExpireLot takes what is left in a lot whose expiry has passed at asOf, as an EXPIRE
 // row pointing at the lot (F12). It locks the wallet before reading the lot again, so
 // it never races a payment for the same balance, and the key expire:{lot_id} makes a
@@ -489,11 +521,15 @@ var walletTypeRules = map[string]walletTypeRule{
 	constants.WalletTxTypeExchangeIn:   {credit: true, currency: constants.WalletCurrencyPoint, referenceTypes: []string{constants.WalletRefTypeWalletTx}, needsGroup: true},
 	constants.WalletTxTypeTransferOut:  {debit: true, referenceTypes: []string{constants.WalletRefTypeWalletTx}, needsGroup: true, needsCounter: true},
 	constants.WalletTxTypeTransferIn:   {credit: true, referenceTypes: []string{constants.WalletRefTypeWalletTx}, needsGroup: true, needsCounter: true},
-	constants.WalletTxTypeGameSpend:    {debit: true, currency: constants.WalletCurrencyCoin, referenceTypes: []string{constants.WalletRefTypeGamePlay}},
-	constants.WalletTxTypeExpire:       {debit: true, referenceTypes: []string{constants.WalletRefTypeLot}},
-	constants.WalletTxTypeAdjustment:   {credit: true, debit: true, referenceTypes: []string{constants.WalletRefTypeUser}, needsActor: true},
-	constants.WalletTxTypeMigration:    {credit: true, referenceTypes: []string{constants.WalletRefTypeLegacyPoints, constants.WalletRefTypeLegacyTokens}},
-	constants.WalletTxTypeRewardRedeem: {debit: true, currency: constants.WalletCurrencyPoint, referenceTypes: []string{constants.WalletRefTypeRewardRedemption}},
+	// GAME_PLAY for the old spin, GAME_SESSION for EnakGame.
+	constants.WalletTxTypeGameSpend:          {debit: true, currency: constants.WalletCurrencyCoin, referenceTypes: []string{constants.WalletRefTypeGamePlay, constants.WalletRefTypeGameSession}},
+	constants.WalletTxTypeGameSpendRefund:    {credit: true, currency: constants.WalletCurrencyCoin, referenceTypes: []string{constants.WalletRefTypeGameSession}, needsReverses: true},
+	constants.WalletTxTypeGameReward:         {credit: true, currency: constants.WalletCurrencyCoin, referenceTypes: []string{constants.WalletRefTypeGameSession}},
+	constants.WalletTxTypeExpire:             {debit: true, referenceTypes: []string{constants.WalletRefTypeLot}},
+	constants.WalletTxTypeAdjustment:         {credit: true, debit: true, referenceTypes: []string{constants.WalletRefTypeUser}, needsActor: true},
+	constants.WalletTxTypeMigration:          {credit: true, referenceTypes: []string{constants.WalletRefTypeLegacyPoints, constants.WalletRefTypeLegacyTokens}},
+	constants.WalletTxTypeRewardRedeem:       {debit: true, currency: constants.WalletCurrencyPoint, referenceTypes: []string{constants.WalletRefTypeRewardRedemption}},
+	constants.WalletTxTypeRewardRedeemRefund: {credit: true, currency: constants.WalletCurrencyPoint, referenceTypes: []string{constants.WalletRefTypeRewardRedemption}, needsReverses: true},
 }
 
 func validateWalletEntry(in *WalletEntry, credit bool) error {