Version: 0.5.6.dev.260314

✨ feat(agent): 重构 Agent 分层并修复普通聊天助手消息未写入 Redis 的问题

🔧 按职责重构 backend/agent 目录为 route/chat/quicknote 三层结构

🔄 将随口记链路拆分为 graph/nodes/tool/state/prompt，其中 graph 仅负责连线

🏃 新增 quicknote runner（方法引用）来收口节点依赖，提升代码可读性

🔀 将控制码分流逻辑抽离到 agent/route，服务层改为薄封装调用

📚 更新相关 README 与测试引用路径，保持原业务逻辑不变

🐛 修复普通聊天链路遗漏 assistant 写入 Redis 的问题（确保 MySQL 和 Redis 的口径一致）

backend/service/agent.go

@@ -6,7 +6,7 @@ import (
 	"strings"
 	"time"
 
-	"github.com/LoveLosita/smartflow/backend/agent"
+	"github.com/LoveLosita/smartflow/backend/agent/chat"
 	"github.com/LoveLosita/smartflow/backend/conv"
 	"github.com/LoveLosita/smartflow/backend/dao"
 	"github.com/LoveLosita/smartflow/backend/inits"
@@ -103,7 +103,7 @@ func (s *AgentService) runNormalChatFlow(
 		chatHistory = conv.ToEinoMessages(histories)
 	}
 
-	historyBudget := pkg.HistoryTokenBudgetByModel(resolvedModelName, agent.SystemPrompt, userMessage)
+	historyBudget := pkg.HistoryTokenBudgetByModel(resolvedModelName, chat.SystemPrompt, userMessage)
 	trimmedHistory, totalHistoryTokens, keptHistoryTokens, droppedCount := pkg.TrimHistoryByTokenBudget(chatHistory, historyBudget)
 	chatHistory = trimmedHistory
 
@@ -127,7 +127,7 @@ func (s *AgentService) runNormalChatFlow(
 		}
 	}
 
-	fullText, streamErr := agent.StreamChat(ctx, selectedModel, resolvedModelName, userMessage, ifThinking, chatHistory, outChan, traceID, chatID, requestStart)
+	fullText, streamErr := chat.StreamChat(ctx, selectedModel, resolvedModelName, userMessage, ifThinking, chatHistory, outChan, traceID, chatID, requestStart)
 	if streamErr != nil {
 		pushErrNonBlocking(errChan, streamErr)
 		return
@@ -147,6 +147,12 @@ func (s *AgentService) runNormalChatFlow(
 		return
 	}
 
+	// 普通聊天链路也需要把助手回复写入 Redis，
+	// 否则会出现“数据库有助手消息，但 Redis 最新会话只有用户消息”的口径不一致。
+	if err = s.agentCache.PushMessage(context.Background(), chatID, &schema.Message{Role: schema.Assistant, Content: fullText}); err != nil {
+		log.Printf("写入助手消息到 Redis 失败: %v", err)
+	}
+
 	if saveErr := s.saveChatHistoryReliable(context.Background(), model.ChatHistoryPersistPayload{
 		UserID:         userID,
 		ConversationID: chatID,