Add IsFree subscription toggle to bypass all tier limitations

- Add IsFree boolean field to UserSubscription model
- When IsFree is true, user sees limitations_enabled=false regardless of global setting
- CheckLimit() bypasses all limit checks for IsFree users
- Add admin endpoint GET /api/admin/subscriptions/user/:user_id
- Add IsFree toggle to admin user detail page under Subscription card
- Add database migration 004_subscription_is_free
- Add integration tests for IsFree functionality
- Add task kanban categorization documentation

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

internal/admin/dto/requests.go

@@ -236,6 +236,7 @@ type SubscriptionFilters struct {
 type UpdateSubscriptionRequest struct {
 	Tier         *string `json:"tier" binding:"omitempty,oneof=free premium pro"`
 	AutoRenew    *bool   `json:"auto_renew"`
+	IsFree       *bool   `json:"is_free"`
 	Platform     *string `json:"platform" binding:"omitempty,max=20"`
 	SubscribedAt *string `json:"subscribed_at"`
 	ExpiresAt    *string `json:"expires_at"`

internal/admin/dto/responses.go

@@ -258,6 +258,7 @@ type SubscriptionResponse struct {
 	Tier         string  `json:"tier"`
 	Platform     string  `json:"platform"`
 	AutoRenew    bool    `json:"auto_renew"`
+	IsFree       bool    `json:"is_free"`
 	SubscribedAt *string `json:"subscribed_at,omitempty"`
 	ExpiresAt    *string `json:"expires_at,omitempty"`
 	CancelledAt  *string `json:"cancelled_at,omitempty"`

internal/admin/handlers/subscription_handler.go

@@ -143,6 +143,9 @@ func (h *AdminSubscriptionHandler) Update(c *gin.Context) {
 	if req.AutoRenew != nil {
 		subscription.AutoRenew = *req.AutoRenew
 	}
+	if req.IsFree != nil {
+		subscription.IsFree = *req.IsFree
+	}
 
 	if err := h.db.Save(&subscription).Error; err != nil {
 		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to update subscription"})
@@ -153,6 +156,44 @@ func (h *AdminSubscriptionHandler) Update(c *gin.Context) {
 	c.JSON(http.StatusOK, h.toSubscriptionResponse(&subscription))
 }
 
+// GetByUser handles GET /api/admin/subscriptions/user/:user_id
+func (h *AdminSubscriptionHandler) GetByUser(c *gin.Context) {
+	userID, err := strconv.ParseUint(c.Param("user_id"), 10, 32)
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "Invalid user ID"})
+		return
+	}
+
+	var subscription models.UserSubscription
+	err = h.db.
+		Preload("User").
+		Where("user_id = ?", userID).
+		First(&subscription).Error
+
+	if err != nil {
+		if err == gorm.ErrRecordNotFound {
+			// Create a default subscription for the user
+			subscription = models.UserSubscription{
+				UserID:    uint(userID),
+				Tier:      models.TierFree,
+				AutoRenew: true,
+				IsFree:    false,
+			}
+			if err := h.db.Create(&subscription).Error; err != nil {
+				c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to create subscription"})
+				return
+			}
+			// Reload with user
+			h.db.Preload("User").First(&subscription, subscription.ID)
+		} else {
+			c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to fetch subscription"})
+			return
+		}
+	}
+
+	c.JSON(http.StatusOK, h.toSubscriptionResponse(&subscription))
+}
+
 // GetStats handles GET /api/admin/subscriptions/stats
 func (h *AdminSubscriptionHandler) GetStats(c *gin.Context) {
 	var total, free, premium, pro int64
@@ -177,6 +218,7 @@ func (h *AdminSubscriptionHandler) toSubscriptionResponse(sub *models.UserSubscr
 		Tier:      string(sub.Tier),
 		Platform:  sub.Platform,
 		AutoRenew: sub.AutoRenew,
+		IsFree:    sub.IsFree,
 		CreatedAt: sub.CreatedAt.Format("2006-01-02T15:04:05Z"),
 	}
 

internal/admin/routes.go

@@ -142,6 +142,7 @@ func SetupRoutes(router *gin.Engine, db *gorm.DB, cfg *config.Config, deps *Depe
 			{
 				subscriptions.GET("", subscriptionHandler.List)
 				subscriptions.GET("/stats", subscriptionHandler.GetStats)
+				subscriptions.GET("/user/:user_id", subscriptionHandler.GetByUser)
 				subscriptions.GET("/:id", subscriptionHandler.Get)
 				subscriptions.PUT("/:id", subscriptionHandler.Update)
 			}