feat: 数据概览简化 + 用户管理增加余额/提现列

- 数据概览：去掉代付统计独立卡片，总收入中以小标签显示代付金额
- 数据概览：移除余额统计区块（余额改在用户管理中展示）
- 数据概览：恢复转化率卡片（唯一付费用户/总用户）
- 用户管理：用户列表新增「余额/提现」列，显示钱包余额和已提现金额
- 后端：DBUsersList 增加 user_balances 查询，返回 walletBalance 字段
- 后端：User model 添加 WalletBalance 非数据库字段
- 包含之前的小程序埋点和管理后台点击统计面板

Made-with: Cursor

soul-api/internal/handler/admin_rfm.go

@@ -304,3 +304,70 @@ func DBUsersJourneyStats(c *gin.Context) {
 	c.JSON(http.StatusOK, gin.H{"success": true, "stats": stats})
 }
 
+// journeyUserItem 用户旅程列表项
+type journeyUserItem struct {
+	ID        string `json:"id"`
+	Nickname  string `json:"nickname"`
+	Phone     string `json:"phone"`
+	CreatedAt string `json:"createdAt"`
+}
+
+// DBUsersJourneyUsers GET /api/db/users/journey-users?stage=xxx&limit=20 — 按阶段查用户
+func DBUsersJourneyUsers(c *gin.Context) {
+	db := database.DB()
+	stage := strings.TrimSpace(c.Query("stage"))
+	limitStr := c.DefaultQuery("limit", "20")
+	limit := 20
+	if n, err := strconv.Atoi(limitStr); err == nil && n > 0 {
+		limit = n
+	}
+	if limit > 100 {
+		limit = 100
+	}
+
+	var users []model.User
+	switch stage {
+	case "register":
+		db.Order("created_at DESC").Limit(limit).Find(&users)
+	case "browse":
+		subq := db.Table("user_tracks").Select("user_id").Where("action = ?", "view_chapter").Distinct("user_id")
+		db.Where("id IN (?)", subq).Order("created_at DESC").Limit(limit).Find(&users)
+	case "bind_phone":
+		db.Where("phone IS NOT NULL AND phone != ''").Order("created_at DESC").Limit(limit).Find(&users)
+	case "first_pay":
+		db.Where("id IN (?)", db.Model(&model.Order{}).Select("user_id").
+			Where("status IN ?", []string{"paid", "success", "completed"})).
+			Order("created_at DESC").Limit(limit).Find(&users)
+	case "fill_profile":
+		db.Where("mbti IS NOT NULL OR industry IS NOT NULL").Order("created_at DESC").Limit(limit).Find(&users)
+	case "match":
+		subq := db.Table("user_tracks").Select("user_id").Where("action = ?", "match").Distinct("user_id")
+		db.Where("id IN (?)", subq).Order("created_at DESC").Limit(limit).Find(&users)
+	case "vip":
+		db.Where("is_vip = ?", true).Order("created_at DESC").Limit(limit).Find(&users)
+	case "distribution":
+		db.Where("referral_code IS NOT NULL AND referral_code != ''").Where("COALESCE(earnings, 0) > ?", 0).
+			Order("created_at DESC").Limit(limit).Find(&users)
+	default:
+		c.JSON(http.StatusBadRequest, gin.H{"success": false, "error": "无效的 stage 参数"})
+		return
+	}
+
+	list := make([]journeyUserItem, 0, len(users))
+	for _, u := range users {
+		nick, phone := "", ""
+		if u.Nickname != nil {
+			nick = *u.Nickname
+		}
+		if u.Phone != nil {
+			phone = *u.Phone
+		}
+		list = append(list, journeyUserItem{
+			ID:        u.ID,
+			Nickname:  nick,
+			Phone:     phone,
+			CreatedAt: u.CreatedAt.Format(time.RFC3339),
+		})
+	}
+	c.JSON(http.StatusOK, gin.H{"success": true, "users": list})
+}