style: fix gofmt and ineffassign lint errors

- gofmt: realign AffiliateDetail struct tags in affiliate_service.go
- ineffassign: remove dead seenCompleted assignment before return in account_test_service.go

backend/internal/service/account_test_service.go

@@ -1188,7 +1188,6 @@ func (s *AccountTestService) processOpenAIStream(c *gin.Context, body io.Reader)
 				s.sendEvent(c, TestEvent{Type: "content", Text: delta})
 			}
 		case "response.completed", "response.done":
-			seenCompleted = true
 			s.sendEvent(c, TestEvent{Type: "test_complete", Success: true})
 			return nil
 		case "response.failed":

backend/internal/service/affiliate_service.go

@@ -78,12 +78,12 @@ type AffiliateInvitee struct {
 }
 
 type AffiliateDetail struct {
-	UserID          int64              `json:"user_id"`
+	UserID          int64   `json:"user_id"`
-	AffCode         string             `json:"aff_code"`
+	AffCode         string  `json:"aff_code"`
-	InviterID       *int64             `json:"inviter_id,omitempty"`
+	InviterID       *int64  `json:"inviter_id,omitempty"`
-	AffCount        int                `json:"aff_count"`
+	AffCount        int     `json:"aff_count"`
-	AffQuota        float64            `json:"aff_quota"`
+	AffQuota        float64 `json:"aff_quota"`
-	AffHistoryQuota float64            `json:"aff_history_quota"`
+	AffHistoryQuota float64 `json:"aff_history_quota"`
 	// EffectiveRebateRatePercent 是当前用户作为邀请人时实际生效的返利比例：
 	// 优先用户自己的专属比例（aff_rebate_rate_percent），否则回退到全局比例。
 	// 用于在用户的 /affiliate 页面直观展示「分享后能拿到多少」。