feat(agents): 优化聊天历史面板和复制功能

- 为聊天历史面板添加加载更多功能，支持分页加载会话列表
- 优化会话列表按时间降序排序和日期分组逻辑
- 统一复制功能使用工具函数，改进错误处理
- 修复兑换码管理菜单路径缺少斜杠的问题
- 优化Dify服务用户标识生成，按agentId隔离会话
- 重构Dify服务扣费逻辑，提取通用处理方法

yudao-module-tik/src/main/java/cn/iocoder/yudao/module/tik/dify/service/DifyServiceImpl.java

@@ -25,6 +25,7 @@ import java.util.HashMap;
 import java.util.Map;
 import java.util.concurrent.atomic.AtomicLong;
 import java.util.concurrent.atomic.AtomicReference;
+import java.util.function.Consumer;
 
 /**
  * Dify 服务实现类
@@ -53,8 +54,8 @@ public class DifyServiceImpl implements DifyService {
         AtomicReference<String> conversationIdRef = new AtomicReference<>(reqVO.getConversationId());
         // 用于存储 token 使用信息
         AtomicReference<DifyChatRespVO> tokenUsageRef = new AtomicReference<>();
-        // Dify 用户标识（固定格式）
-        String difyUserId = "user-" + userId;
+        // Dify 用户标识（按 agentId 隔离会话）
+        String difyUserId = "user-" + userId + "-agent-" + reqVO.getAgentId();
 
         return Mono.fromCallable(() -> {
                     // 1. 获取智能体配置
@@ -179,8 +180,10 @@ public class DifyServiceImpl implements DifyService {
         AtomicReference<String> conversationIdRef = new AtomicReference<>("");
         // 用于存储 token 使用信息
         AtomicReference<DifyChatRespVO> tokenUsageRef = new AtomicReference<>();
-        // Dify 用户标识（固定格式）
-        String difyUserId = "user-" + userId;
+        // Dify 用户标识（按 agentId 隔离会话，无 agentId 时使用默认）
+        String difyUserId = reqVO.getAgentId() != null
+            ? "user-" + userId + "-agent-" + reqVO.getAgentId()
+            : "user-" + userId;
 
         return Mono.fromCallable(() -> {
                     // 1. 获取系统提示词
@@ -653,6 +656,78 @@ public class DifyServiceImpl implements DifyService {
      */
     private record PromptAnalysisContext(String prompt, String apiKey, Integer consumePoints) {}
 
+    /**
+     * 通用的流式响应扣费处理
+     */
+    private void handlePointsDeduction(AtomicLong pendingRecordId,
+                                       AtomicReference<DifyChatRespVO> tokenUsageRef,
+                                       String logPrefix) {
+        if (pendingRecordId.get() <= 0) return;
+        try {
+            DifyChatRespVO tokenUsage = tokenUsageRef.get();
+            if (tokenUsage != null) {
+                pointsService.confirmPendingDeductWithTokens(
+                        pendingRecordId.get(),
+                        tokenUsage.getInputTokens(),
+                        tokenUsage.getOutputTokens(),
+                        tokenUsage.getTotalTokens()
+                );
+                log.info("[{}] 流结束，确认扣费（带token），记录ID: {}, tokens: {}",
+                        logPrefix, pendingRecordId.get(), tokenUsage.getTotalTokens());
+            } else {
+                pointsService.confirmPendingDeduct(pendingRecordId.get());
+                log.info("[{}] 流结束，确认扣费（无token），记录ID: {}", logPrefix, pendingRecordId.get());
+            }
+        } catch (Exception e) {
+            log.error("[{}] 确认扣费失败", logPrefix, e);
+        }
+    }
+
+    /**
+     * 通用的取消预扣处理
+     */
+    private void handlePointsCancellation(AtomicLong pendingRecordId, String logPrefix) {
+        if (pendingRecordId.get() <= 0) return;
+        try {
+            pointsService.cancelPendingDeduct(pendingRecordId.get());
+            log.info("[{}] 流出错，取消预扣，记录ID: {}", logPrefix, pendingRecordId.get());
+        } catch (Exception e) {
+            log.error("[{}] 取消预扣失败", logPrefix, e);
+        }
+    }
+
+    /**
+     * 通用的用户取消扣费处理
+     */
+    private void handleUserCancellation(AtomicLong pendingRecordId, String logPrefix) {
+        if (pendingRecordId.get() <= 0) return;
+        try {
+            pointsService.confirmPendingDeduct(pendingRecordId.get());
+            log.info("[{}] 用户取消，确认扣费，记录ID: {}", logPrefix, pendingRecordId.get());
+        } catch (Exception e) {
+            log.error("[{}] 用户取消后扣费失败", logPrefix, e);
+        }
+    }
+
+    /**
+     * 构建 done 事件 Mono
+     */
+    private Mono<DifyChatRespVO> buildDoneMono(AtomicReference<String> conversationIdRef,
+                                               AtomicReference<DifyChatRespVO> tokenUsageRef) {
+        return Mono.defer(() -> {
+            DifyChatRespVO tokenUsage = tokenUsageRef.get();
+            if (tokenUsage != null) {
+                return Mono.just(DifyChatRespVO.doneWithTokens(
+                        conversationIdRef.get(), null,
+                        tokenUsage.getInputTokens(),
+                        tokenUsage.getOutputTokens(),
+                        tokenUsage.getTotalTokens()
+                ));
+            }
+            return Mono.just(DifyChatRespVO.done(conversationIdRef.get(), null));
+        });
+    }
+
     @Override
     public DifyConversationListRespVO getConversations(Long agentId, String userId, String lastId, Integer limit) {
         // 获取智能体配置
@@ -666,8 +741,8 @@ public class DifyServiceImpl implements DifyService {
                 AiPlatformEnum.DIFY.getPlatform(),
                 AiModelTypeEnum.DIFY_WRITING_STANDARD.getModelCode());
 
-        // Dify 用户标识
-        String difyUserId = "user-" + userId;
+        // Dify 用户标识（按 agentId 隔离会话）
+        String difyUserId = "user-" + userId + "-agent-" + agentId;
 
         DifyConversationListRespVO result = difyClient.getConversations(config.getApiKey(), difyUserId, lastId, limit);
 
@@ -696,8 +771,8 @@ public class DifyServiceImpl implements DifyService {
                 AiPlatformEnum.DIFY.getPlatform(),
                 AiModelTypeEnum.DIFY_WRITING_STANDARD.getModelCode());
 
-        // Dify 用户标识
-        String difyUserId = "user-" + userId;
+        // Dify 用户标识（按 agentId 隔离会话）
+        String difyUserId = "user-" + userId + "-agent-" + agentId;
 
         DifyMessageListRespVO result = difyClient.getMessages(config.getApiKey(), conversationId, difyUserId, firstId, limit);