feat: QQ主动消息管道 + 戳一戳事件 + thinker提示词优化

- ProactiveTarget 结构体 + QQ目标正则解析（extractProactiveMessage 返回双值）
- storeThought 双路推送：platform消息 → platformMessagePusher，web消息 → messagePusher
- platform-bridge: SendProactive接口 + ProactiveSender + /api/v1/internal/send-proactive端点
- QQ戳一戳/notice事件 → noticeToUnified → ContentType "action"
- thinker提示词注入QQ频道上下文：群名称(群号)、活跃时间、trigger-aware引导
- SetBotUID/SetPlatformMessagePusher/AddOrUpdatePlatformChannel 方法
- ai-core source 增加 BotUID/GroupName，platform-bridge source 增加 bot_uid/group_name
- 支持 [CQ:at,qq=xxx] @提及标签自动拼接

Co-Authored-By: Claude <noreply@anthropic.com>

backend/ai-core/cmd/main.go

@@ -373,6 +373,37 @@ func main() {
 			}
 		})
 		log.Printf("[主动消息] 推送已启用 (Gateway=%s)", gatewayURL)
+
+		// 设置平台主动消息推送回调（调用 Platform Bridge 内部 API）
+		platformBridgeURL := getEnv("PLATFORM_BRIDGE_URL", "http://localhost:8082")
+		thinker.SetPlatformMessagePusher(func(target background.ProactiveTarget, message string) {
+			reqBody, _ := json.Marshal(map[string]string{
+				"platform":   target.Platform,
+				"chat_type":  target.ChatType,
+				"user_id":    target.UserID,
+				"group_id":   target.GroupID,
+				"at_user_id": target.AtUserID,
+				"content":    message,
+			})
+			req, _ := http.NewRequest("POST",
+				platformBridgeURL+"/api/v1/internal/send-proactive",
+				strings.NewReader(string(reqBody)))
+			req.Header.Set("Content-Type", "application/json")
+			req.Header.Set("X-Internal-Token", internalToken)
+			resp, err := proactiveClient.Do(req)
+			if err != nil {
+				log.Printf("[主动消息] 平台推送失败: %v", err)
+				return
+			}
+			resp.Body.Close()
+			if resp.StatusCode == http.StatusOK {
+				log.Printf("[主动消息] 已推送到 Platform Bridge: target=%s/%s user=%s group=%s len=%d",
+					target.Platform, target.ChatType, target.UserID, target.GroupID, len(message))
+			} else {
+				log.Printf("[主动消息] Platform Bridge 返回 %d", resp.StatusCode)
+			}
+		})
+		log.Printf("[主动消息] 平台推送已启用 (PlatformBridge=%s)", platformBridgeURL)
 	} else {
 		log.Println("[主动消息] 未配置 INTERNAL_SERVICE_TOKEN，主动消息推送已禁用")
 	}
@@ -825,6 +856,8 @@ func handleChat(
 				ChannelType string `json:"channel_type"`
 				SenderName  string `json:"sender_name"`
 				OriginalUID string `json:"original_uid"`
+				BotUID      string `json:"bot_uid"`
+				GroupName   string `json:"group_name,omitempty"`
 			} `json:"source,omitempty"`
 	}
 	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
@@ -840,6 +873,12 @@ func handleChat(
 	if req.Mode == "platform_silent" {
 		if thinker != nil {
 			thinker.RecordUserMessage(req.SessionID)
+			if req.Source.Platform != "" && req.Source.BotUID != "" {
+				thinker.SetBotUID(req.Source.Platform, req.Source.BotUID)
+			}
+			if req.Source.Platform != "" && req.Source.ChannelID != "" {
+				thinker.AddOrUpdatePlatformChannel(req.Source.Platform, req.Source.ChannelType, req.Source.ChannelID, req.Source.GroupName)
+			}
 		}
 		// 图片预处理：静默观察时也分析图片内容，供后台思考使用
 		message := req.Message
@@ -870,6 +909,12 @@ func handleChat(
 	// 0. 记录用户活动（重置闲置计时器）
 	if thinker != nil {
 		thinker.RecordUserMessage(req.SessionID)
+		if req.Source.Platform != "" && req.Source.BotUID != "" {
+			thinker.SetBotUID(req.Source.Platform, req.Source.BotUID)
+		}
+		if req.Source.Platform != "" && req.Source.ChannelID != "" {
+			thinker.AddOrUpdatePlatformChannel(req.Source.Platform, req.Source.ChannelType, req.Source.ChannelID, req.Source.GroupName)
+		}
 	}
 
 	// Admin private messages: redirect to the main admin session so conversation
@@ -911,6 +956,8 @@ func handleChat(
 		Mode:        req.Mode,
 		Nickname:    userNickname,
 		ChannelType: req.Source.ChannelType,
+		ChannelID:   req.Source.ChannelID,
+		BotUID:      req.Source.BotUID,
 	})
 	if err != nil {
 		errData, _ := json.Marshal(map[string]string{"delta": "", "error": fmt.Sprintf("处理失败: %v", err)})