fix: Campaign Create 400 + Reports 500 + 种子数据补全

修复:
- campaign_handler.go: Campaign创建JSON解析报VALIDATION_ERROR
- analytics_query_helpers.go: Reports标签/团队维度500(SQL query)
- bootstrap.go: 补充Campaign种子数据确保测试环境完整

backend/internal/handler/api/v1/campaign_handler.go

@@ -78,15 +78,27 @@ func (h *CampaignHandler) Create(c *gin.Context) {
 		return
 	}
 
-	// Chatwoot: params.require(:campaign) → request body must be {"campaign": {...}}
+	// Accept both wrapped {"campaign": {...}} (Chatwoot style) and flat {...} payloads.
+	// The frontend sends flat payload, so we prefer that format.
+	var req service.CreateCampaignRequest
 	var wrapper struct {
 		Campaign service.CreateCampaignRequest `json:"campaign"`
 	}
-	if err := c.ShouldBindJSON(&wrapper); err != nil {
-		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, err.Error())
+	rawBody, err := c.GetRawData()
+	if err != nil {
+		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "cannot read request body")
 		return
 	}
-	req := wrapper.Campaign
+	// Try wrapped format first (Chatwoot style)
+	if err := json.Unmarshal(rawBody, &wrapper); err == nil && wrapper.Campaign.Title != "" {
+		req = wrapper.Campaign
+	} else {
+		// Fall back to flat format (GoChat style - what the frontend sends)
+		if err := json.Unmarshal(rawBody, &req); err != nil {
+			response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, err.Error())
+			return
+		}
+	}
 
 	campaign, svcErr := h.svc.Create(c.Request.Context(), accountID, req)
 	if svcErr != nil {