fix(log): F6 polish — log datasource create error log + schema patches for auth_type/token/headers + ES default index sync on datasource select

backend/controller/log_datasource.go

@@ -6,6 +6,7 @@ import (
 	"encoding/json"
 	"errors"
 	"io"
+	"log"
 	"net/http"
 	"strings"
 	"time"
@@ -76,6 +77,8 @@ func (h *LogDSHandler) Create(c *gin.Context) {
 		IsDefault: req.IsDefault, Status: 1,
 	}
 	if err := h.db.Create(&ds).Error; err != nil {
+		// 记录详细错误，便于排查字段缺失/唯一约束等数据库问题 // Logan.Li
+		log.Printf("[LogDataSource] 创建数据源失败: %v", err)
 		if errors.Is(err, gorm.ErrDuplicatedKey) {
 			c.JSON(409, model.Response{Code: 409, Message: "数据源名称已存在"})
 			return