feat(dashboard): add admin user analytics and fix chart labels

- Add GET /api/data/users endpoint for user-grouped quota data (admin only)
- Add user consumption ranking (horizontal bar, top 10) and user consumption
  trend (area chart) tabs visible only to admin users
- Fix mislabeled "消耗趋势" tab to "调用趋势" (shows call counts, not quota)
- Add processUserData helper for user ranking and trend data extraction
- Add i18n keys for new tabs across all 7 locales

controller/usedata.go

@@ -27,6 +27,21 @@ func GetAllQuotaDates(c *gin.Context) {
 	return
 }
 
+func GetQuotaDatesByUser(c *gin.Context) {
+	startTimestamp, _ := strconv.ParseInt(c.Query("start_timestamp"), 10, 64)
+	endTimestamp, _ := strconv.ParseInt(c.Query("end_timestamp"), 10, 64)
+	dates, err := model.GetQuotaDataGroupByUser(startTimestamp, endTimestamp)
+	if err != nil {
+		common.ApiError(c, err)
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{
+		"success": true,
+		"message": "",
+		"data":    dates,
+	})
+}
+
 func GetUserQuotaDates(c *gin.Context) {
 	userId := c.GetInt("id")
 	startTimestamp, _ := strconv.ParseInt(c.Query("start_timestamp"), 10, 64)