feat: 管理面板补齐(RAG导入/记忆添加/会话接history/诚实表述) + design/16 §4.6 IM多会话隔离+第三方身份+黑白名单

agent-98 面板批次:
- 会话管理面板改接 history.ListSessions(主web+次级) + 新建次级会话按钮
- 记忆面板手动添加入口 POST /admin/memories(owner)
- 知识库真正实现 IndexDocument(分块+落projectindex) + POST /admin/rag 导入端点
- 三面板空态诚实表述(去除'后端M10+提供')
- RAG嵌入降级到keyword/line(无直属embedder,不伪造语义,符合红线)

agent-99 design/16 §4.6:
- model.Message.SenderName + 迁移0006 sender_name 列
- 第三方身份边界: session.ResolveActor判定(非LLM猜) + [第三方·昵称]前缀(不改源content)
- 群聊/陌生人落独立sess-xxx(persistIsolated),不写主会话,不广播
- 黑/白名单(allowGroups/denyGroups/allowUsers/denyUsers)最前拦截,不进LLM
- 多账号 CHANNELS_JSON 配置 + 每平台多实例
- 管理只读 GET /admin/channels/{platform}/messages(该平台非主人消息流)

实机验证(JWT): 会话管理返回主会话web / 记忆添加成功 / RAG导入documents非空+Cyrene命中; 后端build/vet/test全绿 + 前端build绿

internal/services/gateway/history.go

@@ -34,7 +34,11 @@ type historyMessage struct {
 	Thinking  string `json:"thinking,omitempty"`
 	Platform  string `json:"platform,omitempty"`
 	DeviceID  string `json:"deviceId,omitempty"`
-	CreatedAt int64  `json:"createdAt"`
+	// SenderName is the human-readable sender display name of a third-party
+	// message (group/stranger, design/16 §4.6). It is blank for the owner's
+	// private chat on the main session, so empty means "labeled as the owner".
+	SenderName string `json:"senderName,omitempty"`
+	CreatedAt  int64  `json:"createdAt"`
 }
 
 // handleHistorySessions returns the main session first, then every sub session (oldest
@@ -125,6 +129,52 @@ func (s *Server) handleListMessages(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, http.StatusOK, out)
 }
 
+// handleChannelPlatformLog returns up to limit messages for an IM platform across its
+// isolated (group/stranger) sessions, newest first, for the admin adapter log page
+// (design/16 §4.6 §4). It excludes the fixed main web session, so only the platform's
+// non-owner message stream is surfaced; the owner-private mirror stays out of this view.
+func (s *Server) handleChannelPlatformLog(w http.ResponseWriter, r *http.Request) {
+	if s.history == nil {
+		writeError(w, &apperr.AppError{Code: "not_implemented", Message: "会话历史服务未配置（未注入 HistoryStore）", HTTPCode: http.StatusNotImplemented})
+		return
+	}
+	platform := r.PathValue("platform")
+	if platform == "" {
+		writeError(w, apperr.Wrap(apperr.ErrBadRequest, "bad_request", "platform is required"))
+		return
+	}
+	limitStr := r.URL.Query().Get("limit")
+	limit := historyDefaultLimit
+	if limitStr != "" {
+		v, err := strconv.Atoi(limitStr)
+		if err != nil || v < 1 {
+			writeError(w, apperr.Wrap(apperr.ErrBadRequest, "bad_request", "invalid limit"))
+			return
+		}
+		limit = v
+	}
+	var before int64
+	if b := r.URL.Query().Get("before"); b != "" {
+		v, err := strconv.ParseInt(b, 10, 64)
+		if err != nil {
+			writeError(w, apperr.Wrap(apperr.ErrBadRequest, "bad_request", "invalid before"))
+			return
+		}
+		before = v
+	}
+	msgs, err := s.history.ListPlatformLog(r.Context(), platform, before, limit)
+	if err != nil {
+		s.log.Error("history platform log", "err", err, "platform", platform)
+		writeError(w, apperr.Wrap(apperr.ErrInternal, "platform_log_failed", "failed to list platform log"))
+		return
+	}
+	out := make([]historyMessage, 0, len(msgs))
+	for _, m := range msgs {
+		out = append(out, toHistoryMessage(m))
+	}
+	writeJSON(w, http.StatusOK, out)
+}
+
 // handleDeleteSession deletes a sub session and all its messages. The main session is
 // immutable (design/16 §6) and returns 403.
 func (s *Server) handleDeleteSession(w http.ResponseWriter, r *http.Request) {
@@ -160,9 +210,10 @@ func toHistoryMessage(m history.Message) historyMessage {
 		Mood:      m.Mood,
 		Image:     m.Image,
 		Thinking:  m.Thinking,
-		Platform:  m.Platform,
-		DeviceID:  m.DeviceID,
-		CreatedAt: m.CreatedAt,
+		Platform:   m.Platform,
+		DeviceID:   m.DeviceID,
+		SenderName: m.SenderName,
+		CreatedAt:  m.CreatedAt,
 	}
 }