refactor(loyalty): remove what is left of tokens

Tokens are EnakCoin and no app uses the token names any more, so their
compatibility layer goes:

- GET /customer/tokens and its handler, service, processor and response
  types.
- total_tokens and tokens_history on GET /customer/wallet; last_updated
  now comes from the most recent row of either currency.
- token_used and tokens_remaining on game and spin responses, and
  sort_by=token_used on the game play list.
- TOKENS as a campaign type and reward type, with the mapping to COINS:
  migration 000092 already renamed the stored values.

The customer_tokens table and its entity stay, as cmd/wallet-migrate still
reads them, and LEGACY_TOKENS stays as the reference of the MIGRATION rows
it wrote. The docs list the removed names and their replacements.

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

internal/mappers/campaign_mapper.go

@@ -71,7 +71,7 @@ func ToCampaignEntity(request *contract.CreateCampaignRequest) *entities.Campaig
 	return &entities.Campaign{
 		Name:        request.Name,
 		Description: request.Description,
-		Type:        entities.NormalizeCampaignType(request.Type),
+		Type:        entities.CampaignType(request.Type),
 		StartDate:   request.StartDate,
 		EndDate:     request.EndDate,
 		IsActive:    request.IsActive,
@@ -91,7 +91,7 @@ func ToCampaignEntityFromUpdate(request *contract.UpdateCampaignRequest) *entiti
 		ID:          request.ID,
 		Name:        request.Name,
 		Description: request.Description,
-		Type:        entities.NormalizeCampaignType(request.Type),
+		Type:        entities.CampaignType(request.Type),
 		StartDate:   request.StartDate,
 		EndDate:     request.EndDate,
 		IsActive:    request.IsActive,
@@ -118,7 +118,7 @@ func ToCampaignRuleEntity(request *contract.CampaignRuleStruct, campaignID uuid.
 		CampaignID:     campaignID,
 		RuleType:       entities.RuleType(request.RuleType),
 		ConditionValue: request.ConditionValue,
-		RewardType:     entities.NormalizeCampaignRewardType(request.RewardType),
+		RewardType:     entities.CampaignRewardType(request.RewardType),
 		RewardValue:    request.RewardValue,
 		RewardSubtype:  rewardSubtype,
 		RewardRefID:    request.RewardRefID,
@@ -142,7 +142,7 @@ func ToCampaignRuleEntityFromUpdate(request *contract.CampaignRuleStruct, campai
 		CampaignID:     campaignID,
 		RuleType:       entities.RuleType(request.RuleType),
 		ConditionValue: request.ConditionValue,
-		RewardType:     entities.NormalizeCampaignRewardType(request.RewardType),
+		RewardType:     entities.CampaignRewardType(request.RewardType),
 		RewardValue:    request.RewardValue,
 		RewardSubtype:  rewardSubtype,
 		RewardRefID:    request.RewardRefID,

internal/mappers/spin_game_mapper.go

@@ -36,10 +36,9 @@ func SpinGameResponseDataModelToContract(data *models.SpinGameResponseData) *con
 	}
 
 	return &contract.SpinGameResponseData{
-		GamePlay:        GamePlayResponseModelToContract(&data.GamePlay),
-		PrizeWon:        CustomerGamePrizeResponseModelToContract(data.PrizeWon),
-		CoinsRemaining:  data.CoinsRemaining,
-		TokensRemaining: data.CoinsRemaining,
+		GamePlay:       GamePlayResponseModelToContract(&data.GamePlay),
+		PrizeWon:       CustomerGamePrizeResponseModelToContract(data.PrizeWon),
+		CoinsRemaining: data.CoinsRemaining,
 	}
 }
 
@@ -55,7 +54,6 @@ func GamePlayResponseModelToContract(resp *models.GamePlayResponse) contract.Gam
 		CustomerID: resp.CustomerID,
 		PrizeID:    resp.PrizeID,
 		CoinsUsed:  resp.CoinsUsed,
-		TokenUsed:  resp.CoinsUsed,
 		RandomSeed: resp.RandomSeed,
 		CreatedAt:  resp.CreatedAt,
 		Game:       nil, // Optional field - can be populated separately if needed