fix: 消息日志增强 + 历史消息抑制 + SSE实时追踪 + 群聊上下文优化

- 日志：收/发消息均显示群名称，管理员显示真实QQ昵称而非"开拓者"
- 历史消息：服务重启后NapCat回放的历史消息不再触发回复，静默注入上下文
- 消息时间戳：转发给AI时附带【消息时间: HH:MM:SS (XmXs前)】标记
- ♪ 分割符：QQ消息支持♪作为句子断点
- AI-Core SSE端点：全链路追踪实时推送，ethend不再5秒轮询
- 群聊上下文：AI-Core明确被告知消息来自群聊，以实际发送者为主语

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

backend/platform-bridge/internal/adapter/qq/adapter.go

@@ -34,8 +34,12 @@ type Adapter struct {
 	conn           *websocket.Conn
 	connMu         sync.Mutex
 	connected      bool
+	connectedAt    time.Time // when the connection was established (for historical message detection)
 	srv            *http.Server // HTTP server for WS upgrades (server mode only)
 
+	groupNames   map[int64]string    // group ID → group name cache
+	groupNamesMu sync.RWMutex
+
 	pendingResponses map[string]chan *OBv11APIResponse
 	respMu           sync.Mutex
 }
@@ -52,6 +56,7 @@ func NewAdapter(configName, mode, port, accessToken, remoteURL string, sendInter
 		remoteURL:        remoteURL,
 		sendIntervalMs:   sendIntervalMs,
 		pendingResponses: make(map[string]chan *OBv11APIResponse),
+		groupNames:       make(map[int64]string),
 	}
 }
 
@@ -60,6 +65,76 @@ func (a *Adapter) ConfigName() string    { return a.configName }
 func (a *Adapter) SendIntervalMs() int   { return a.sendIntervalMs }
 func (a *Adapter) SelfID() string        { return a.selfID }
 
+// ConnectedAt returns the time the connection was established, for historical message detection.
+func (a *Adapter) ConnectedAt() time.Time {
+	a.connMu.Lock()
+	defer a.connMu.Unlock()
+	return a.connectedAt
+}
+
+// GroupName resolves a group ID to its name. Returns empty string if unknown.
+func (a *Adapter) GroupName(groupID int64) string {
+	a.groupNamesMu.RLock()
+	n, ok := a.groupNames[groupID]
+	a.groupNamesMu.RUnlock()
+	if ok {
+		return n
+	}
+	// Try to resolve via API.
+	a.fetchGroupName(groupID)
+	return ""
+}
+
+// SetGroupName caches a group name for a group ID.
+func (a *Adapter) SetGroupName(groupID int64, name string) {
+	a.groupNamesMu.Lock()
+	a.groupNames[groupID] = name
+	a.groupNamesMu.Unlock()
+}
+
+// fetchGroupName tries to resolve a group name via NapCat HTTP API (client mode).
+func (a *Adapter) fetchGroupName(groupID int64) {
+	if a.mode != "client" || a.remoteURL == "" {
+		return
+	}
+	// Derive HTTP base from WS URL: ws://host:port → http://host:port
+	httpBase := strings.Replace(a.remoteURL, "ws://", "http://", 1)
+	httpBase = strings.Replace(httpBase, "wss://", "https://", 1)
+	// Strip path suffix if present
+	if idx := strings.LastIndex(httpBase, "/"); idx > 8 {
+		httpBase = httpBase[:idx]
+	}
+
+	go func() {
+		url := fmt.Sprintf("%s/get_group_info?group_id=%d", httpBase, groupID)
+		if a.accessToken != "" {
+			url += "&access_token=" + a.accessToken
+		}
+		ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+		defer cancel()
+		req, err := http.NewRequestWithContext(ctx, "GET", url, nil)
+		if err != nil {
+			return
+		}
+		resp, err := http.DefaultClient.Do(req)
+		if err != nil {
+			return
+		}
+		defer resp.Body.Close()
+		var result struct {
+			Data struct {
+				GroupName string `json:"group_name"`
+			} `json:"data"`
+		}
+		if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
+			return
+		}
+		if result.Data.GroupName != "" {
+			a.SetGroupName(groupID, result.Data.GroupName)
+		}
+	}()
+}
+
 func (a *Adapter) Capabilities() bridge.PlatformCapabilities {
 	return bridge.PlatformCapabilities{
 		MaxMessageLength:   200,
@@ -109,6 +184,7 @@ func (a *Adapter) wsHandler(w http.ResponseWriter, r *http.Request) {
 	}
 	a.conn = conn
 	a.connected = true
+	a.connectedAt = time.Now()
 	a.connMu.Unlock()
 	fmt.Println("[qq] NapCat/OneBot connected (正向WS)")
 }
@@ -148,6 +224,7 @@ func (a *Adapter) connectClient(ctx context.Context) error {
 	}
 	a.conn = conn
 	a.connected = true
+	a.connectedAt = time.Now()
 	a.connMu.Unlock()
 
 	fmt.Printf("[qq] connected to NapCat OneBot WS (client mode): %s\n", a.remoteURL)
@@ -257,6 +334,26 @@ func (a *Adapter) ToUnified(rawMessage interface{}) (*bridge.UnifiedMessage, err
 			}
 		}
 	}
+	// Fallback: parse CQ at codes from string format (e.g. [CQ:at,qq=2254389756]).
+	if len(mentions) == 0 {
+		raw := msg.RawMessage
+		if raw == "" {
+			if s, ok := msg.Message.(string); ok {
+				raw = s
+			}
+		}
+		for _, m := range cqAtRegex.FindAllStringSubmatch(raw, -1) {
+			if len(m) >= 2 {
+				mentions = append(mentions, m[1])
+			}
+		}
+	}
+
+	// Resolve group name for group messages.
+	groupName := ""
+	if msg.MessageType == "group" {
+		groupName = a.GroupName(msg.GroupID)
+	}
 
 	attachments := extractAttachments(msg)
 
@@ -273,6 +370,7 @@ func (a *Adapter) ToUnified(rawMessage interface{}) (*bridge.UnifiedMessage, err
 		Attachments: attachments,
 		RawData:     rawMessage,
 		Timestamp:   time.Unix(msg.Time, 0),
+			GroupName:   groupName,
 	}, nil
 }
 
@@ -416,6 +514,7 @@ func extractText(msg *OBv11Message) string {
 	return ""
 }
 
+var cqAtRegex = regexp.MustCompile(`\[CQ:at,qq=(\d+)\]`)
 var cqImageRegex = regexp.MustCompile(`\[CQ:image,[^\]]*\]`)
 var cqURLRegex = regexp.MustCompile(`\burl=([^,\]]+)`)
 	var boldRegex = regexp.MustCompile(`\*\*(.+?)\*\*`)