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/processor/campaign_processor.go

@@ -70,7 +70,7 @@ func (p *campaignProcessor) ListCampaigns(ctx context.Context, req *contract.Lis
 		Page:      req.Page,
 		Limit:     req.Limit,
 		Search:    req.Search,
-		Type:      string(entities.NormalizeCampaignType(req.Type)),
+		Type:      req.Type,
 		IsActive:  req.IsActive,
 		ShowOnApp: req.ShowOnApp,
 		StartDate: req.StartDate,
@@ -178,7 +178,7 @@ func (p *campaignRuleProcessor) CreateCampaignRule(ctx context.Context, req *con
 		CampaignID:     req.CampaignID,
 		RuleType:       entities.RuleType(req.RuleType),
 		ConditionValue: req.ConditionValue,
-		RewardType:     entities.NormalizeCampaignRewardType(req.RewardType),
+		RewardType:     entities.CampaignRewardType(req.RewardType),
 		RewardValue:    req.RewardValue,
 		RewardSubtype:  (*entities.RewardSubtype)(req.RewardSubtype),
 		RewardRefID:    req.RewardRefID,
@@ -218,7 +218,7 @@ func (p *campaignRuleProcessor) ListCampaignRules(ctx context.Context, req *cont
 		Limit:      req.Limit,
 		CampaignID: req.CampaignID,
 		RuleType:   req.RuleType,
-		RewardType: string(entities.NormalizeCampaignRewardType(req.RewardType)),
+		RewardType: req.RewardType,
 	}
 
 	// Get from repository
@@ -247,7 +247,7 @@ func (p *campaignRuleProcessor) UpdateCampaignRule(ctx context.Context, req *con
 		CampaignID:     req.CampaignID,
 		RuleType:       entities.RuleType(req.RuleType),
 		ConditionValue: req.ConditionValue,
-		RewardType:     entities.NormalizeCampaignRewardType(req.RewardType),
+		RewardType:     entities.CampaignRewardType(req.RewardType),
 		RewardValue:    req.RewardValue,
 		RewardSubtype:  (*entities.RewardSubtype)(req.RewardSubtype),
 		RewardRefID:    req.RewardRefID,