优化分页和筛选功能：实现服务端分页和筛选，修复总数不匹配问题

- 优化设备管理、版本管理、用户管理、在线实例、公告管理页面的分页功能
- 后端添加筛选参数支持（application_id, status, type, search等）
- 前端移除冗余的前端筛选逻辑，改为服务端筛选
- 修复分页总数与筛选数据不匹配的问题
- 优化云端变量记录页面的时间筛选和搜索功能
- 修复DateTimePicker组件关闭后不自动更新的问题

backend/internal/router/admin/users.go

@@ -3,6 +3,7 @@ package admin
 import (
 	"fmt"
 	"log"
+	"strconv"
 	"time"
 	"verification-platform-backend/internal/database"
 	"verification-platform-backend/internal/model"
@@ -57,10 +58,14 @@ func handleGetUsers(c *gin.Context) {
 	userID := c.GetUint("user_id")
 	log.Printf("[DEBUG] handleGetUsers called, userID: %d", userID)
 
-	var users []model.AppUser
-	var appHeartbeatTimeoutMap map[uint]int
+	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
+	pageSize, _ := strconv.Atoi(c.DefaultQuery("page_size", "20"))
 
 	applicationID := c.Query("application_id")
+	statusFilter := c.Query("status")
+
+	var users []model.AppUser
+	var appHeartbeatTimeoutMap map[uint]int
 	if applicationID != "" {
 		var appID uint
 		if _, err := fmt.Sscanf(applicationID, "%d", &appID); err != nil {
@@ -81,8 +86,13 @@ func handleGetUsers(c *gin.Context) {
 		}
 		appHeartbeatTimeoutMap[app.ID] = timeout
 
+		query := database.DB.Preload("Application").Where("application_id = ?", appID)
+		if statusFilter != "" {
+			query = query.Where("status = ?", statusFilter)
+		}
+
 		if app.UserID == userID {
-			if err := database.DB.Preload("Application").Where("application_id = ?", appID).Find(&users).Error; err != nil {
+			if err := query.Find(&users).Error; err != nil {
 				response.Error(c, 500, "获取用户列表失败")
 				return
 			}
@@ -102,7 +112,11 @@ func handleGetUsers(c *gin.Context) {
 			}
 
 			if len(cardUserIDs) > 0 {
-				if err := database.DB.Preload("Application").Where("id IN ?", cardUserIDs).Find(&users).Error; err != nil {
+				query = database.DB.Preload("Application").Where("id IN ?", cardUserIDs)
+				if statusFilter != "" {
+					query = query.Where("status = ?", statusFilter)
+				}
+				if err := query.Find(&users).Error; err != nil {
 					response.Error(c, 500, "获取用户列表失败")
 					return
 				}
@@ -137,7 +151,11 @@ func handleGetUsers(c *gin.Context) {
 		}
 
 		if len(ownAppIDs) > 0 {
-			if err := database.DB.Preload("Application").Where("application_id IN ?", ownAppIDs).Find(&users).Error; err != nil {
+			query := database.DB.Preload("Application").Where("application_id IN ?", ownAppIDs)
+			if statusFilter != "" {
+				query = query.Where("status = ?", statusFilter)
+			}
+			if err := query.Find(&users).Error; err != nil {
 				response.Error(c, 500, "获取用户列表失败")
 				return
 			}
@@ -179,8 +197,12 @@ func handleGetUsers(c *gin.Context) {
 		}
 
 		if len(allCardUserIDs) > 0 {
+			query := database.DB.Preload("Application").Where("id IN ?", allCardUserIDs)
+			if statusFilter != "" {
+				query = query.Where("status = ?", statusFilter)
+			}
 			var appUsers []model.AppUser
-			if err := database.DB.Preload("Application").Where("id IN ?", allCardUserIDs).Find(&appUsers).Error; err != nil {
+			if err := query.Find(&appUsers).Error; err != nil {
 				log.Printf("[DEBUG] Failed to get users: %v", err)
 			} else {
 				users = append(users, appUsers...)
@@ -246,9 +268,21 @@ func handleGetUsers(c *gin.Context) {
 		})
 	}
 
+	offset := (page - 1) * pageSize
+	end := offset + pageSize
+	if offset > len(usersWithStatus) {
+		offset = len(usersWithStatus)
+	}
+	if end > len(usersWithStatus) {
+		end = len(usersWithStatus)
+	}
+	paginatedUsers := usersWithStatus[offset:end]
+
 	responseData := gin.H{
-		"users":         usersWithStatus,
+		"users":         paginatedUsers,
 		"total":         totalCount,
+		"page":          page,
+		"page_size":     pageSize,
 		"online_count":  onlineCount,
 		"offline_count": offlineCount,
 		"banned_count":  bannedCount,