feat(runtime): IM 主人私聊补历史转录（与 Web 主会话同源：抽共享 transcript 包 + OwnerEnvFor 单入口）

internal/services/gateway/session_steer.go

@@ -8,6 +8,7 @@ import (
 	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/history"
 	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/loop"
 	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/model"
+	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/transcript"
 )
 
 // 本文件实现「忙时新消息在回合内边界注入同一回合」的网关侧
@@ -89,7 +90,7 @@ func (s *steerTurn) Steer(ctx context.Context, req loop.SteerRequest) []model.Me
 		sessionID = s.sessionID
 	}
 	o := s.orchestrator
-	reader, ok := o.history.(transcriptReader)
+	reader, ok := o.history.(transcript.Reader)
 	if !ok {
 		return nil
 	}
@@ -99,7 +100,7 @@ func (s *steerTurn) Steer(ctx context.Context, req loop.SteerRequest) []model.Me
 	}
 	// 每个边界都重读转录：设计要求的「最新性＝下一个边界即生效」正是靠这次重读，
 	// 而不是靠回合开始时的那一次播种（design/15 §2.4）。
-	recent, err := reader.Recent(ctx, sessionID, transcriptContextCount)
+	recent, err := reader.Recent(ctx, sessionID, transcript.ContextCount)
 	if err != nil {
 		steerLog(o).Debug("steer transcript read", "session", sessionID, "step", req.Step, "err", err)
 		return nil
@@ -127,7 +128,7 @@ func (s *steerTurn) Steer(ctx context.Context, req loop.SteerRequest) []model.Me
 		// 帧壳必须带本路的 turnId（忙时并行规范草案 §2.5）：真并行下客户端要
 		// 靠它把这条消息配到**正确那一路**的 `turn.end`，否则灰态收不了口。
 		o.emitTurnState(sessionID, s.turnID, wsSteerAck, map[string]any{"messageId": c.row.ID, "atStep": req.Step})
-		out = append(out, transcriptMessage(c.row))
+		out = append(out, transcript.Message(c.row))
 	}
 	steerLog(o).Info("pending steered", "session", sessionID, "step", req.Step, "messages", len(out))
 	return out