Version: 0.9.53.dev.260429

后端：
1. 流式思考链路从 raw reasoning_content 切到 `thinking_summary` 摘要协议，补齐摘要 prompt、digestor 与 Lite 压缩链路，plan / execute / fallback 统一改为“只出摘要、不透原始推理”，正文开始后自动关停摘要流。
2. thinking_summary 打通 timeline / SSE / outbox 持久化闭环，只落 detail_summary 与必要 metadata，并补强 seq 自检、冲突幂等识别与补 seq 回填，提升重放恢复稳定性。
3. 会话历史口径继续收紧，assistant 正文与时间线不再回写 raw reasoning_content，仅保留正文与思考耗时，避免刷新恢复时再次暴露内部推理文本。

前端：
4. 助手页开始接入 thinking_summary 实时流与历史恢复，补齐短摘要状态、长摘要折叠区、正文开流后自动收口，并增加调试入口用于协议联调与验收。
5. 当前前端助手页仍是残次过渡态，本版先以 thinking_summary 协议接通和基础渲染为主，样式、交互与细节体验暂未收平，下一版集中修复。

仓库：
6. 补充 thinking_summary 对接说明，明确 SSE 协议、timeline 恢复口径与 short/detail summary 的使用边界。

backend/newAgent/node/execute/action_router.go

@@ -56,6 +56,15 @@ func collectExecuteDecisionFromLLM(
 	parser := newagentrouter.NewStreamDecisionParser()
 	output := &executeDecisionStreamOutput{firstChunk: true}
 	var fullText strings.Builder
+	reasoningDigestor, digestorErr := emitter.NewReasoningDigestor(ctx, executeSpeakBlockID, executeStageName)
+	if digestorErr != nil {
+		return nil, fmt.Errorf("执行 thinking 摘要器初始化失败: %w", digestorErr)
+	}
+	defer func() {
+		if reasoningDigestor != nil {
+			_ = reasoningDigestor.Close(ctx)
+		}
+	}()
 
 	for {
 		chunk, recvErr := reader.Recv()
@@ -68,15 +77,9 @@ func collectExecuteDecisionFromLLM(
 		}
 
 		if chunk != nil && strings.TrimSpace(chunk.ReasoningContent) != "" {
-			if emitErr := emitter.EmitReasoningText(
-				executeSpeakBlockID,
-				executeStageName,
-				chunk.ReasoningContent,
-				output.firstChunk,
-			); emitErr != nil {
-				return nil, fmt.Errorf("执行 thinking 推送失败: %w", emitErr)
+			if reasoningDigestor != nil {
+				reasoningDigestor.Append(chunk.ReasoningContent)
 			}
-			output.firstChunk = false
 		}
 
 		content := ""
@@ -148,6 +151,9 @@ func collectExecuteDecisionFromLLM(
 		output.decision = decision
 
 		if visible != "" {
+			if reasoningDigestor != nil {
+				reasoningDigestor.MarkContentStarted()
+			}
 			if emitErr := emitter.EmitAssistantText(
 				executeSpeakBlockID,
 				executeStageName,
@@ -174,9 +180,14 @@ func collectExecuteDecisionFromLLM(
 				continue
 			}
 			if strings.TrimSpace(chunk2.ReasoningContent) != "" {
-				_ = emitter.EmitReasoningText(executeSpeakBlockID, executeStageName, chunk2.ReasoningContent, false)
+				if reasoningDigestor != nil {
+					reasoningDigestor.Append(chunk2.ReasoningContent)
+				}
 			}
 			if chunk2.Content != "" {
+				if reasoningDigestor != nil {
+					reasoningDigestor.MarkContentStarted()
+				}
 				if emitErr := emitter.EmitAssistantText(
 					executeSpeakBlockID,
 					executeStageName,