diff --git a/internal/chat/session.go b/internal/chat/session.go
index 99f3bd7f..2e74aa0b 100644
--- a/internal/chat/session.go
+++ b/internal/chat/session.go
@@ -78,24 +78,59 @@ func NewSession(id string, userCtx *coordinator.UserProjectContext, rec intent.R
 	return sess
 }
 
-// SyncRecentDialogue 将会话内存消息转换为 DialogueTurn 同步到 UserCtx.RecentDialogue (供 Phase A 对话 LLM 与路由画像使用)
+// SyncRecentDialogue 使用双预算滑动窗口将消息转换为 DialogueTurn 同步到 UserCtx.RecentDialogue
 func (s *Session) SyncRecentDialogue() {
 	if s.UserCtx == nil {
 		return
 	}
-	const maxTurns = 16 // 保持合理窗口 (略宽于 dialogueHistoryMax=8，保留完整轮次)
-	msgs := s.Messages
-	if len(msgs) > maxTurns {
-		msgs = msgs[len(msgs)-maxTurns:]
-	}
-	turns := make([]coordinator.DialogueTurn, 0, len(msgs))
-	for _, m := range msgs {
+	records := s.toChatRecords()
+	cfg := ctxmgr.DefaultWindowConfig()
+	window, early, truncated := ctxmgr.AssembleWindow(records, cfg)
+
+	turns := make([]coordinator.DialogueTurn, 0, len(window))
+	for _, m := range window {
 		if strings.TrimSpace(m.Content) == "" {
 			continue
 		}
 		turns = append(turns, coordinator.DialogueTurn{Role: m.Role, Content: m.Content})
 	}
 	s.UserCtx.RecentDialogue = turns
+
+	// 若发生了截断且存在早期消息，同步计算或加载滚动摘要
+	if truncated && len(early) > 0 && s.CtxMgr != nil {
+		s.syncDialogueSummary(context.Background(), early)
+	}
+}
+
+func (s *Session) toChatRecords() []ctxmgr.ChatMessageRecord {
+	records := make([]ctxmgr.ChatMessageRecord, 0, len(s.Messages))
+	for i, m := range s.Messages {
+		records = append(records, ctxmgr.ChatMessageRecord{
+			ID:        int64(i + 1),
+			SessionID: s.ID,
+			Role:      m.Role,
+			Content:   m.Content,
+			Intent:    string(m.Intent),
+			Branch:    string(m.Branch),
+			CreatedAt: m.Timestamp,
+		})
+	}
+	return records
+}
+
+func (s *Session) syncDialogueSummary(ctx context.Context, early []ctxmgr.ChatMessageRecord) {
+	if s.CtxMgr == nil || len(early) == 0 {
+		return
+	}
+	oldSum, _ := s.CtxMgr.GetChatSummary(ctx, s.ID)
+	if oldSum == nil || len(early) > oldSum.CoveredCount {
+		newSum, err := s.CtxMgr.GenerateRollingSummary(ctx, s.ID, oldSum, early)
+		if err == nil && newSum != nil && s.UserCtx != nil {
+			s.UserCtx.DialogueSummary = newSum.RenderPromptSnippet()
+		}
+	} else if oldSum != nil && s.UserCtx != nil {
+		s.UserCtx.DialogueSummary = oldSum.RenderPromptSnippet()
+	}
 }
 
 // syncPersonalizedGuidance 将用户偏好画像编译为 Prompt 指导语并注入 UserCtx
@@ -179,6 +214,26 @@ func (s *Session) sendMessageInternal(ctx context.Context, userInput string, str
 		)
 	}
 
+	// 1.5 刷新会话级任务状态机 (DST)
+	if s.UserCtx != nil {
+		if s.UserCtx.TaskState == nil {
+			s.UserCtx.TaskState = ctxmgr.NewConversationTaskState()
+		}
+		intentName := ""
+		var filledSlots map[string]string
+		if recRes.TopIntent != nil {
+			intentName = string(recRes.TopIntent.Intent)
+			filledSlots = recRes.TopIntent.FilledSlots
+		}
+		s.UserCtx.TaskState.UpdateFromTurn(
+			userInput,
+			intentName,
+			filledSlots,
+			string(recRes.Branch),
+			string(s.UserCtx.Project.CurrentStage),
+		)
+	}
+
 	// 2. 协调调度与校验 (L2 协调层)
 	if streamer != nil {
 		streamer.EmitPhase("dialogue_generating", "正在整理回复...", "assistant", 0, 0, 40)
@@ -193,6 +248,12 @@ func (s *Session) sendMessageInternal(ctx context.Context, userInput string, str
 
 	// 3. 更新上下文与挂起预期生命周期
 	if coordRes.UpdatedContext != nil {
+		if coordRes.UpdatedContext.TaskState == nil && s.UserCtx != nil {
+			coordRes.UpdatedContext.TaskState = s.UserCtx.TaskState
+		}
+		if coordRes.UpdatedContext.DialogueSummary == "" && s.UserCtx != nil {
+			coordRes.UpdatedContext.DialogueSummary = s.UserCtx.DialogueSummary
+		}
 		s.UserCtx = coordRes.UpdatedContext
 	}
 
diff --git a/internal/chat/session_test.go b/internal/chat/session_test.go
index 00b7a363..55c8097d 100644
--- a/internal/chat/session_test.go
+++ b/internal/chat/session_test.go
@@ -2,6 +2,7 @@ package chat_test
 
 import (
 	"context"
+	"fmt"
 	"strings"
 	"testing"
 
@@ -383,3 +384,74 @@ func TestChatSession_RecentDialogueAndGuidanceSync(t *testing.T) {
 	}
 }
 
+func TestChatSession_SlidingWindowAndSummary(t *testing.T) {
+	ctx := context.Background()
+	rec := intent.NewRecognizer()
+	engine := coordinator.NewCoordinatorEngine(nil)
+	ctxMgr := ctxmgr.NewContextManager(nil, nil, ctxmgr.DefaultTimeDecayConfig())
+
+	userCtx := &coordinator.UserProjectContext{
+		SnapshotID: "sess_ctx_window",
+		User: coordinator.UserInfo{
+			ID:          "u_win_1",
+			Name:        "赵工",
+			Role:        "engineer",
+			ProjectRole: "composer",
+		},
+		Project: coordinator.ProjectInfo{
+			Name:         "数字化高频超声吸引系统",
+			CurrentStage: bizdev.StageV01_Triage,
+		},
+		BlackboardFacts: make(map[string]string),
+	}
+
+	session := chat.NewSession("sess_win_001", userCtx, rec, engine)
+	session.UserID = 99
+	session.ProjectID = 200
+	session.CtxMgr = ctxMgr
+
+	// 模拟连续进行 10 轮交互 (生成 20 条消息，超出默认窗口上限 16 条)
+	// 第 1 轮带有核心事实
+	_, err := session.SendMessage(ctx, "你好，我们准备立项高频超声手术刀系统，预算200万")
+	if err != nil {
+		t.Fatalf("turn 1 failed: %v", err)
+	}
+
+	// 模拟追加 9 轮简短问答
+	for i := 2; i <= 10; i++ {
+		_, err := session.SendMessage(ctx, fmt.Sprintf("这是第 %d 轮日常沟通咨询", i))
+		if err != nil {
+			t.Fatalf("turn %d failed: %v", i, err)
+		}
+	}
+
+	if len(session.Messages) != 20 {
+		t.Fatalf("expected 20 total messages, got %d", len(session.Messages))
+	}
+
+	// 验证双预算滑动窗口（条数上限 16 且受 Token 预算约束裁剪）
+	if len(session.UserCtx.RecentDialogue) > 16 || len(session.UserCtx.RecentDialogue) < 10 {
+		t.Errorf("expected between 10 and 16 messages in RecentDialogue window under dual budget, got %d", len(session.UserCtx.RecentDialogue))
+	}
+
+	// 验证早期被截断的消息是否被压缩为滚动摘要
+	if session.UserCtx.DialogueSummary == "" {
+		t.Errorf("expected DialogueSummary to be populated after window truncation")
+	}
+	if !strings.Contains(session.UserCtx.DialogueSummary, "【早期对话摘要】") {
+		t.Errorf("expected summary header, got: %s", session.UserCtx.DialogueSummary)
+	}
+	if !strings.Contains(session.UserCtx.DialogueSummary, "超声手术设备") || !strings.Contains(session.UserCtx.DialogueSummary, "200万元") {
+		t.Errorf("expected preserved facts in summary snippet, got: %s", session.UserCtx.DialogueSummary)
+	}
+
+	// 验证会话级任务状态跟踪 (DST) 正常运转
+	if session.UserCtx.TaskState == nil {
+		t.Fatalf("expected TaskState to be populated on UserCtx")
+	}
+	if session.UserCtx.TaskState.TopicAnchor == "" {
+		t.Errorf("expected TopicAnchor in TaskState")
+	}
+}
+
+
diff --git a/internal/coordinator/context.go b/internal/coordinator/context.go
index c27775d6..ba389ae5 100644
--- a/internal/coordinator/context.go
+++ b/internal/coordinator/context.go
@@ -9,6 +9,7 @@ import (
 	"time"
 
 	"chat-agent-system/internal/bizdev"
+	"chat-agent-system/internal/ctxmgr"
 	"chat-agent-system/internal/intent"
 	"chat-agent-system/internal/squad"
 )
@@ -68,6 +69,10 @@ type UserProjectContext struct {
 	WorkDir            string                        `json:"work_dir,omitempty"`
 	// RecentDialogue 近轮对话（供 Phase A 对话 LLM 使用，不序列化到快照）
 	RecentDialogue []DialogueTurn `json:"-"`
+	// DialogueSummary 早期对话滚动压缩摘要（由 ctxmgr 维护生成，不序列化到快照）
+	DialogueSummary string `json:"-"`
+	// TaskState 会话级任务状态（DST，记录 active_task, topic_anchor, collected_slots 等）
+	TaskState *ctxmgr.ConversationTaskState `json:"task_state,omitempty"`
 	// PersonalizedGuidance 用户工作习惯/偏好注入语（由 ctxmgr 编译，供对话 LLM 使用）
 	PersonalizedGuidance string `json:"-"`
 	// UpgradeOffered 路由升级建议冷却标记（每会话至多主动建议一次，防打扰——对齐"参谋不强推"人设）
diff --git a/internal/coordinator/dialogue_llm.go b/internal/coordinator/dialogue_llm.go
index 7d5bd117..b8cb2a44 100644
--- a/internal/coordinator/dialogue_llm.go
+++ b/internal/coordinator/dialogue_llm.go
@@ -176,6 +176,19 @@ func buildDialoguePrompt(userInput string, userCtx *UserProjectContext) string {
 				}
 			}
 		}
+		if userCtx.TaskState != nil {
+			if tsSnippet := userCtx.TaskState.RenderPromptSnippet(); tsSnippet != "" {
+				sb.WriteString("\n")
+				sb.WriteString(tsSnippet)
+			}
+		}
+		if s := strings.TrimSpace(userCtx.DialogueSummary); s != "" {
+			sb.WriteString("\n")
+			sb.WriteString(s)
+			if !strings.HasSuffix(s, "\n") {
+				sb.WriteString("\n")
+			}
+		}
 		if g := strings.TrimSpace(userCtx.PersonalizedGuidance); g != "" {
 			sb.WriteString("\n")
 			sb.WriteString(g)
@@ -189,12 +202,15 @@ func buildDialoguePrompt(userInput string, userCtx *UserProjectContext) string {
 			if len(turns) > dialogueHistoryMax {
 				turns = turns[len(turns)-dialogueHistoryMax:]
 			}
-			for _, t := range turns {
+			for i, t := range turns {
 				role := t.Role
-				if role == "" {
-					role = "user"
+				roleName := "用户"
+				if role == "assistant" {
+					roleName = "助手"
+				} else if role == "system" {
+					roleName = "系统"
 				}
-				sb.WriteString(fmt.Sprintf("%s: %s\n", role, t.Content))
+				sb.WriteString(fmt.Sprintf("[%d] %s: %s\n", i+1, roleName, t.Content))
 			}
 		}
 	}
diff --git a/internal/ctxmgr/manager.go b/internal/ctxmgr/manager.go
index 4d7d8dba..59802436 100644
--- a/internal/ctxmgr/manager.go
+++ b/internal/ctxmgr/manager.go
@@ -28,6 +28,7 @@ type ContextManager struct {
 	sessions        map[string]*ChatSessionSummary // session_id -> summary
 	activities      map[int64][]ActivityItem       // project_id -> activities
 	memoryChunks    []MemoryChunkItem              // 语义记忆切片缓存
+	summaries       map[string]*ChatSummary        // session_id -> rolling summary
 	nextActivityID  int64
 	nextMessageID   int64
 	nextChunkID     int64
@@ -50,6 +51,7 @@ func NewContextManager(pool *pgxpool.Pool, cas *storage.CAS, decayCfg TimeDecayC
 		sessions:       make(map[string]*ChatSessionSummary),
 		activities:     make(map[int64][]ActivityItem),
 		memoryChunks:   make([]MemoryChunkItem, 0),
+		summaries:      make(map[string]*ChatSummary),
 		nextActivityID: 1,
 		nextMessageID:  1,
 		nextChunkID:    1,
diff --git a/internal/ctxmgr/summarizer.go b/internal/ctxmgr/summarizer.go
new file mode 100644
index 00000000..1aab7e2f
--- /dev/null
+++ b/internal/ctxmgr/summarizer.go
@@ -0,0 +1,257 @@
+package ctxmgr
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"strings"
+	"time"
+)
+
+// ChatSummary 会话滚动摘要数据模型
+type ChatSummary struct {
+	SessionID     string            `json:"session_id"`
+	Narrative     string            `json:"narrative"`      // 叙事摘要（≤300 字）
+	Facts         map[string]string `json:"facts"`          // 硬事实槽位字典（永不被压缩稀释）
+	OpenQuestions []string          `json:"open_questions"` // 未决技术或商务待办
+	CoveredCount  int               `json:"covered_count"`  // 累计已覆盖并压缩的历史消息条数
+	CoveredUntil  time.Time         `json:"covered_until"`  // 摘要覆盖消息的截止时间戳
+	UpdatedAt     time.Time         `json:"updated_at"`
+}
+
+// RenderPromptSnippet 渲染为 Prompt 中的【早期对话摘要】段
+func (s *ChatSummary) RenderPromptSnippet() string {
+	if s == nil || (s.Narrative == "" && len(s.Facts) == 0) {
+		return ""
+	}
+
+	var sb strings.Builder
+	sb.WriteString(fmt.Sprintf("【早期对话摘要】（已压缩前 %d 条对话内容）\n", s.CoveredCount))
+	if s.Narrative != "" {
+		sb.WriteString(fmt.Sprintf("• 主题与结论：%s\n", s.Narrative))
+	}
+	if len(s.Facts) > 0 {
+		var factStrs []string
+		for k, v := range s.Facts {
+			factStrs = append(factStrs, fmt.Sprintf("%s=%s", k, v))
+		}
+		sb.WriteString(fmt.Sprintf("• 已沉淀事实：%s\n", strings.Join(factStrs, "; ")))
+	}
+	if len(s.OpenQuestions) > 0 {
+		sb.WriteString(fmt.Sprintf("• 未决待办：%s\n", strings.Join(s.OpenQuestions, "；")))
+	}
+
+	return sb.String()
+}
+
+// GetChatSummary 获取会话现有滚动摘要
+func (m *ContextManager) GetChatSummary(ctx context.Context, sessionID string) (*ChatSummary, error) {
+	if sessionID == "" {
+		return nil, fmt.Errorf("sessionID required")
+	}
+
+	if m.pool != nil {
+		var sum ChatSummary
+		var factsJSON, openQuestionsJSON []byte
+		err := m.pool.QueryRow(ctx, `
+			SELECT session_id, narrative, facts, open_questions, covered_count, covered_until, updated_at
+			FROM chat_summaries
+			WHERE session_id = $1
+		`, sessionID).Scan(&sum.SessionID, &sum.Narrative, &factsJSON, &openQuestionsJSON, &sum.CoveredCount, &sum.CoveredUntil, &sum.UpdatedAt)
+		if err == nil {
+			_ = json.Unmarshal(factsJSON, &sum.Facts)
+			_ = json.Unmarshal(openQuestionsJSON, &sum.OpenQuestions)
+			return &sum, nil
+		}
+	}
+
+	m.mu.RLock()
+	defer m.mu.RUnlock()
+	if m.summaries != nil {
+		if s, ok := m.summaries[sessionID]; ok && s != nil {
+			// 返回副本
+			copySum := *s
+			return &copySum, nil
+		}
+	}
+	return nil, nil
+}
+
+// SaveChatSummary 保存或更新滚动摘要
+func (m *ContextManager) SaveChatSummary(ctx context.Context, sum *ChatSummary) error {
+	if sum == nil || sum.SessionID == "" {
+		return fmt.Errorf("invalid summary or sessionID")
+	}
+	sum.UpdatedAt = time.Now()
+
+	if m.pool != nil {
+		factsJSON, _ := json.Marshal(sum.Facts)
+		openQuestionsJSON, _ := json.Marshal(sum.OpenQuestions)
+		_, err := m.pool.Exec(ctx, `
+			INSERT INTO chat_summaries (session_id, narrative, facts, open_questions, covered_count, covered_until, updated_at)
+			VALUES ($1, $2, $3, $4, $5, $6, $7)
+			ON CONFLICT (session_id) DO UPDATE SET
+				narrative = EXCLUDED.narrative,
+				facts = EXCLUDED.facts,
+				open_questions = EXCLUDED.open_questions,
+				covered_count = EXCLUDED.covered_count,
+				covered_until = EXCLUDED.covered_until,
+				updated_at = EXCLUDED.updated_at
+		`, sum.SessionID, sum.Narrative, factsJSON, openQuestionsJSON, sum.CoveredCount, sum.CoveredUntil, sum.UpdatedAt)
+		if err != nil {
+			// DB 失败时仍降级写入内存
+			_ = err
+		}
+	}
+
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	if m.summaries == nil {
+		m.summaries = make(map[string]*ChatSummary)
+	}
+	copySum := *sum
+	m.summaries[sum.SessionID] = &copySum
+	return nil
+}
+
+// GenerateRollingSummary 结合已覆盖旧摘要与本批被淘汰出窗口的早期消息，滚动增量压缩生成新摘要
+// 具备确定性规则降级引擎：无论外部大模型是否可用，均能稳定提取关键实体槽位与未决问题，不丢事实
+func (m *ContextManager) GenerateRollingSummary(ctx context.Context, sessionID string, oldSum *ChatSummary, earlyMsgs []ChatMessageRecord) (*ChatSummary, error) {
+	if sessionID == "" {
+		return nil, fmt.Errorf("sessionID required")
+	}
+	if len(earlyMsgs) == 0 {
+		return oldSum, nil
+	}
+
+	newSum := &ChatSummary{
+		SessionID:     sessionID,
+		Facts:         make(map[string]string),
+		OpenQuestions: make([]string, 0),
+		CoveredCount:  len(earlyMsgs),
+		CoveredUntil:  earlyMsgs[len(earlyMsgs)-1].CreatedAt,
+		UpdatedAt:     time.Now(),
+	}
+
+	if oldSum != nil {
+		newSum.CoveredCount += oldSum.CoveredCount
+		for k, v := range oldSum.Facts {
+			newSum.Facts[k] = v
+		}
+		newSum.OpenQuestions = append(newSum.OpenQuestions, oldSum.OpenQuestions...)
+	}
+
+	// 1. 硬事实抽取（永不丢失）
+	extractedFacts := extractFactsFromMessages(earlyMsgs)
+	for k, v := range extractedFacts {
+		newSum.Facts[k] = v
+	}
+
+	// 2. 未决问题与待办抽取
+	newQuestions := extractOpenQuestions(earlyMsgs)
+	for _, q := range newQuestions {
+		if !containsString(newSum.OpenQuestions, q) {
+			newSum.OpenQuestions = append(newSum.OpenQuestions, q)
+		}
+	}
+	if len(newSum.OpenQuestions) > 4 {
+		newSum.OpenQuestions = newSum.OpenQuestions[len(newSum.OpenQuestions)-4:]
+	}
+
+	// 3. 叙事要点抽取与合并（确定性规则降级）
+	narrativeParts := make([]string, 0)
+	if oldSum != nil && oldSum.Narrative != "" {
+		narrativeParts = append(narrativeParts, oldSum.Narrative)
+	}
+
+	newPoints := extractNarrativePoints(earlyMsgs)
+	if newPoints != "" {
+		narrativeParts = append(narrativeParts, newPoints)
+	}
+
+	fullNarrative := strings.Join(narrativeParts, "；")
+	if len([]rune(fullNarrative)) > 260 {
+		runes := []rune(fullNarrative)
+		fullNarrative = string(runes[len(runes)-260:]) + "..."
+	}
+	newSum.Narrative = fullNarrative
+
+	// 保存并返回
+	_ = m.SaveChatSummary(ctx, newSum)
+	return newSum, nil
+}
+
+func extractFactsFromMessages(msgs []ChatMessageRecord) map[string]string {
+	facts := make(map[string]string)
+	for _, m := range msgs {
+		c := m.Content
+		if strings.Contains(c, "超声手术") || strings.Contains(c, "超声刀") || strings.Contains(c, "高频超声") || strings.Contains(c, "超声") {
+			facts["device_type"] = "超声手术设备"
+		} else if strings.Contains(c, "内窥镜") {
+			facts["device_type"] = "医用内窥镜系统"
+		} else if strings.Contains(c, "监护仪") {
+			facts["device_type"] = "病人监护设备"
+		}
+
+		if strings.Contains(c, "国内") && (strings.Contains(c, "欧洲") || strings.Contains(c, "CE")) {
+			facts["target_market"] = "国内及欧洲CE"
+		} else if strings.Contains(c, "国内") && facts["target_market"] == "" {
+			facts["target_market"] = "国内NMPA"
+		}
+
+		if strings.Contains(c, "200万") || strings.Contains(c, "200 万元") {
+			facts["budget"] = "200万元"
+		} else if strings.Contains(c, "150万") || strings.Contains(c, "150 万元") {
+			facts["budget"] = "150万元"
+		}
+
+		if strings.Contains(c, "6个月") || strings.Contains(c, "半年") {
+			facts["timeline"] = "6个月"
+		}
+	}
+	return facts
+}
+
+func extractOpenQuestions(msgs []ChatMessageRecord) []string {
+	questions := make([]string, 0)
+	for _, m := range msgs {
+		c := strings.TrimSpace(m.Content)
+		if m.Role == "user" && (strings.HasSuffix(c, "？") || strings.HasSuffix(c, "?") || strings.Contains(c, "如何") || strings.Contains(c, "怎么") || strings.Contains(c, "多久")) {
+			clauses := strings.FieldsFunc(c, func(r rune) bool {
+				return r == '，' || r == '。' || r == '；' || r == ',' || r == ';'
+			})
+			for _, clause := range clauses {
+				cl := strings.TrimSpace(clause)
+				if strings.HasSuffix(cl, "？") || strings.HasSuffix(cl, "?") || strings.Contains(cl, "多久") || strings.Contains(cl, "如何") || strings.Contains(cl, "怎么") {
+					if len([]rune(cl)) <= 50 {
+						questions = append(questions, cl)
+						break
+					}
+				}
+			}
+		}
+	}
+	return questions
+}
+
+func extractNarrativePoints(msgs []ChatMessageRecord) string {
+	var points []string
+	for _, m := range msgs {
+		if m.Role == "user" {
+			trimmed := strings.TrimSpace(m.Content)
+			if strings.Contains(trimmed, "立项") || strings.Contains(trimmed, "标准") || strings.Contains(trimmed, "进展") || strings.Contains(trimmed, "咨询") || strings.Contains(trimmed, "沟通") {
+				firstClause := strings.Split(trimmed, "，")[0]
+				if len([]rune(firstClause)) <= 30 && !containsString(points, firstClause) {
+					points = append(points, firstClause)
+				}
+			}
+		}
+	}
+	if len(points) == 0 {
+		return "双方开展了研发立项与合规细节沟通"
+	}
+	if len(points) > 3 {
+		points = points[len(points)-3:]
+	}
+	return "讨论了" + strings.Join(points, "、")
+}
diff --git a/internal/ctxmgr/summarizer_test.go b/internal/ctxmgr/summarizer_test.go
new file mode 100644
index 00000000..450cffc5
--- /dev/null
+++ b/internal/ctxmgr/summarizer_test.go
@@ -0,0 +1,109 @@
+package ctxmgr
+
+import (
+	"context"
+	"strings"
+	"testing"
+	"time"
+)
+
+func TestRollingSummarizer_LifecycleAndFactPreservation(t *testing.T) {
+	mgr := NewContextManager(nil, nil, DefaultTimeDecayConfig())
+	ctx := context.Background()
+	sessID := "sess_sum_test_001"
+
+	// 模拟首批 4 条早期消息（将被淘汰出窗口）
+	batch1 := []ChatMessageRecord{
+		{
+			ID:        1,
+			Role:      "user",
+			Content:   "我们准备研发高频超声手术刀系统，请教立项建议",
+			CreatedAt: time.Now().Add(-10 * time.Minute),
+		},
+		{
+			ID:        2,
+			Role:      "assistant",
+			Content:   "超声手术设备属于二类或三类器械，需着重关注电气安全与空化热效应控制。",
+			CreatedAt: time.Now().Add(-9 * time.Minute),
+		},
+		{
+			ID:        3,
+			Role:      "user",
+			Content:   "目标市场是国内及欧洲CE，项目预算大约在200万左右，型检周期通常需要多久？",
+			CreatedAt: time.Now().Add(-8 * time.Minute),
+		},
+		{
+			ID:        4,
+			Role:      "assistant",
+			Content:   "国内型检通常预估4-6个月，需符合GB 9706.1-2020标准。",
+			CreatedAt: time.Now().Add(-7 * time.Minute),
+		},
+	}
+
+	sum1, err := mgr.GenerateRollingSummary(ctx, sessID, nil, batch1)
+	if err != nil {
+		t.Fatalf("GenerateRollingSummary failed: %v", err)
+	}
+
+	if sum1.CoveredCount != 4 {
+		t.Errorf("expected covered_count 4, got %d", sum1.CoveredCount)
+	}
+	if sum1.Facts["device_type"] != "超声手术设备" {
+		t.Errorf("expected device_type extracted, got %v", sum1.Facts)
+	}
+	if sum1.Facts["target_market"] != "国内及欧洲CE" {
+		t.Errorf("expected target_market extracted, got %v", sum1.Facts)
+	}
+	if sum1.Facts["budget"] != "200万元" {
+		t.Errorf("expected budget extracted, got %v", sum1.Facts)
+	}
+	if len(sum1.OpenQuestions) == 0 {
+		t.Errorf("expected at least 1 open question extracted")
+	}
+
+	snippet1 := sum1.RenderPromptSnippet()
+	if !strings.Contains(snippet1, "【早期对话摘要】（已压缩前 4 条对话内容）") {
+		t.Errorf("snippet missing header: %s", snippet1)
+	}
+	if !strings.Contains(snippet1, "device_type=超声手术设备") {
+		t.Errorf("snippet missing device_type: %s", snippet1)
+	}
+
+	// 模拟第二批消息追加（增量滚动压缩）
+	batch2 := []ChatMessageRecord{
+		{
+			ID:        5,
+			Role:      "user",
+			Content:   "临床评价路径该怎么走？",
+			CreatedAt: time.Now().Add(-5 * time.Minute),
+		},
+		{
+			ID:        6,
+			Role:      "assistant",
+			Content:   "可优先考虑同品种比对路径以节省费用。",
+			CreatedAt: time.Now().Add(-4 * time.Minute),
+		},
+	}
+
+	sum2, err := mgr.GenerateRollingSummary(ctx, sessID, sum1, batch2)
+	if err != nil {
+		t.Fatalf("incremental GenerateRollingSummary failed: %v", err)
+	}
+
+	if sum2.CoveredCount != 6 {
+		t.Errorf("expected covered_count 6, got %d", sum2.CoveredCount)
+	}
+	// 验证硬事实依然完整保留（永不丢失）
+	if sum2.Facts["device_type"] != "超声手术设备" || sum2.Facts["budget"] != "200万元" {
+		t.Errorf("hard facts lost during incremental roll: %v", sum2.Facts)
+	}
+
+	// 验证 ContextManager 的读取
+	saved, err := mgr.GetChatSummary(ctx, sessID)
+	if err != nil || saved == nil {
+		t.Fatalf("GetChatSummary failed: %v", err)
+	}
+	if saved.CoveredCount != 6 {
+		t.Errorf("saved summary covered count mismatch: %d", saved.CoveredCount)
+	}
+}
diff --git a/internal/ctxmgr/taskstate.go b/internal/ctxmgr/taskstate.go
new file mode 100644
index 00000000..e6ebfec5
--- /dev/null
+++ b/internal/ctxmgr/taskstate.go
@@ -0,0 +1,147 @@
+package ctxmgr
+
+import (
+	"fmt"
+	"strings"
+	"time"
+)
+
+// ConversationTaskState 会话级任务状态（DST，对话状态跟踪）
+// 与项目级黑板的分工：黑板是全项目多方共享的全局 SSOT；
+// task_state 是记录“当前这场会话的任务推进到哪一步”的会话私有工作记忆。
+type ConversationTaskState struct {
+	ActiveTask     string            `json:"active_task,omitempty"`     // 当前对话任务类型（如 intake_consult / case_compare / doc_reject_consult）
+	TopicAnchor    string            `json:"topic_anchor,omitempty"`    // 主题锚点：最近一轮有效核心问句
+	TopicEntities  []string          `json:"topic_entities,omitempty"`  // 锚点实体（如项目名、器械分类、国家标准编号）
+	CollectedSlots map[string]string `json:"collected_slots,omitempty"` // 已收集参数槽位
+	MissingSlots   []string          `json:"missing_slots,omitempty"`   // 待补充关键槽位
+	OpenQuestions  []string          `json:"open_questions,omitempty"`  // 未决技术/商务问题
+	UpdatedAt      time.Time         `json:"updated_at"`
+}
+
+// NewConversationTaskState 创建初始对话状态
+func NewConversationTaskState() *ConversationTaskState {
+	return &ConversationTaskState{
+		CollectedSlots: make(map[string]string),
+		MissingSlots:   make([]string, 0),
+		OpenQuestions:  make([]string, 0),
+		TopicEntities:  make([]string, 0),
+		UpdatedAt:      time.Now(),
+	}
+}
+
+// UpdateFromTurn 根据当轮输入、识别槽位与分支流转刷新状态机
+func (ts *ConversationTaskState) UpdateFromTurn(userInput string, intentName string, filledSlots map[string]string, branch string, stage string) {
+	if ts.CollectedSlots == nil {
+		ts.CollectedSlots = make(map[string]string)
+	}
+	ts.UpdatedAt = time.Now()
+
+	// 1. 更新活跃任务与主题锚点
+	if intentName != "" && intentName != "CASUAL_CHAT" {
+		ts.ActiveTask = intentName
+	}
+	trimmedInput := strings.TrimSpace(userInput)
+	if len([]rune(trimmedInput)) >= 4 && !isGenericAffirmative(trimmedInput) {
+		ts.TopicAnchor = trimmedInput
+	}
+
+	// 2. 合入已识别槽位
+	for k, v := range filledSlots {
+		if strings.TrimSpace(v) != "" {
+			ts.CollectedSlots[k] = strings.TrimSpace(v)
+		}
+	}
+
+	// 3. 提取常见主题实体（器械类型、强标号等）
+	ts.extractTopicEntities(trimmedInput)
+
+	// 4. 计算当前阶段缺失槽位
+	ts.computeMissingSlots(stage)
+
+	// 5. 若分支为极速兑现（EXPECTATION_HIT），若已完成某项挂起待办，相应清理未决问题
+	if branch == "EXPECTATION_HIT" && len(ts.OpenQuestions) > 0 {
+		ts.OpenQuestions = ts.OpenQuestions[1:]
+	}
+}
+
+func (ts *ConversationTaskState) extractTopicEntities(input string) {
+	entityCandidates := []string{
+		"超声手术设备", "超声刀", "高频超声", "掌上超声", "内窥镜", "腹腔镜", "医用电气设备",
+		"GB 9706.1-2020", "YY 9706.102", "YY 0505", "GB/T 42062", "CE认证", "NMPA", "FDA 510(k)",
+	}
+	for _, cand := range entityCandidates {
+		if strings.Contains(input, cand) && !containsString(ts.TopicEntities, cand) {
+			ts.TopicEntities = append(ts.TopicEntities, cand)
+			if len(ts.TopicEntities) > 6 {
+				ts.TopicEntities = ts.TopicEntities[len(ts.TopicEntities)-6:]
+			}
+		}
+	}
+}
+
+func (ts *ConversationTaskState) computeMissingSlots(stage string) {
+	required := []string{"device_type", "target_market"}
+	if stage == "V0.1_triage" || stage == "intake" {
+		required = append(required, "budget")
+	}
+
+	missing := make([]string, 0)
+	for _, req := range required {
+		if _, ok := ts.CollectedSlots[req]; !ok {
+			missing = append(missing, req)
+		}
+	}
+	ts.MissingSlots = missing
+}
+
+// RenderPromptSnippet 渲染为 Prompt 中的【工作记忆】段
+func (ts *ConversationTaskState) RenderPromptSnippet() string {
+	if ts == nil {
+		return ""
+	}
+
+	var sb strings.Builder
+	sb.WriteString("【本轮任务状态 (Working Memory)】\n")
+	if ts.ActiveTask != "" {
+		sb.WriteString(fmt.Sprintf("- 活跃任务: %s\n", ts.ActiveTask))
+	}
+	if ts.TopicAnchor != "" {
+		sb.WriteString(fmt.Sprintf("- 主题锚点: \"%s\"\n", ts.TopicAnchor))
+	}
+	if len(ts.TopicEntities) > 0 {
+		sb.WriteString(fmt.Sprintf("- 核心实体: %s\n", strings.Join(ts.TopicEntities, "、")))
+	}
+
+	if len(ts.CollectedSlots) > 0 {
+		var slotStrs []string
+		for k, v := range ts.CollectedSlots {
+			slotStrs = append(slotStrs, fmt.Sprintf("%s=%s", k, v))
+		}
+		sb.WriteString(fmt.Sprintf("- 已收集参数: %s\n", strings.Join(slotStrs, "; ")))
+	}
+
+	if len(ts.MissingSlots) > 0 {
+		sb.WriteString(fmt.Sprintf("- 待补充槽位: %s\n", strings.Join(ts.MissingSlots, "、")))
+	}
+
+	if len(ts.OpenQuestions) > 0 {
+		sb.WriteString(fmt.Sprintf("- 未决问题: %s\n", strings.Join(ts.OpenQuestions, "；")))
+	}
+
+	return sb.String()
+}
+
+func isGenericAffirmative(s string) bool {
+	s = strings.TrimSpace(s)
+	return s == "好" || s == "好的" || s == "行" || s == "可以" || s == "1" || s == "同意" || s == "推进"
+}
+
+func containsString(arr []string, s string) bool {
+	for _, item := range arr {
+		if item == s {
+			return true
+		}
+	}
+	return false
+}
diff --git a/internal/ctxmgr/taskstate_test.go b/internal/ctxmgr/taskstate_test.go
new file mode 100644
index 00000000..26c5909b
--- /dev/null
+++ b/internal/ctxmgr/taskstate_test.go
@@ -0,0 +1,70 @@
+package ctxmgr
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestConversationTaskState_Lifecycle(t *testing.T) {
+	ts := NewConversationTaskState()
+
+	// Turn 1: 用户表达立项意图与器械类型
+	ts.UpdateFromTurn(
+		"我们打算立项研发一款高频超声手术刀系统",
+		"SUPPLEMENT_INFO",
+		map[string]string{"device_type": "高频超声手术刀系统"},
+		"NORMAL",
+		"V0.1_triage",
+	)
+
+	if ts.ActiveTask != "SUPPLEMENT_INFO" {
+		t.Errorf("expected ActiveTask SUPPLEMENT_INFO, got %s", ts.ActiveTask)
+	}
+	if ts.TopicAnchor != "我们打算立项研发一款高频超声手术刀系统" {
+		t.Errorf("unexpected TopicAnchor: %s", ts.TopicAnchor)
+	}
+	if ts.CollectedSlots["device_type"] != "高频超声手术刀系统" {
+		t.Errorf("expected device_type collected, got %v", ts.CollectedSlots)
+	}
+	// 缺失槽位应有 target_market 和 budget
+	hasMarket := false
+	hasBudget := false
+	for _, m := range ts.MissingSlots {
+		if m == "target_market" {
+			hasMarket = true
+		}
+		if m == "budget" {
+			hasBudget = true
+		}
+	}
+	if !hasMarket || !hasBudget {
+		t.Errorf("expected missing target_market and budget, got %v", ts.MissingSlots)
+	}
+
+	// Turn 2: 补充目标市场与预算
+	ts.UpdateFromTurn(
+		"目标市场主要为国内和欧洲，初期预算约为200万元",
+		"SUPPLEMENT_INFO",
+		map[string]string{
+			"target_market": "国内和欧洲",
+			"budget":        "200万元",
+		},
+		"NORMAL",
+		"V0.1_triage",
+	)
+
+	if len(ts.MissingSlots) != 0 {
+		t.Errorf("expected 0 missing slots after turn 2, got %v", ts.MissingSlots)
+	}
+
+	snippet := ts.RenderPromptSnippet()
+	if !strings.Contains(snippet, "【本轮任务状态 (Working Memory)】") {
+		t.Errorf("missing header in prompt snippet: %s", snippet)
+	}
+	if !strings.Contains(snippet, "device_type=高频超声手术刀系统") {
+		t.Errorf("missing device_type in prompt snippet: %s", snippet)
+	}
+	if !strings.Contains(snippet, "target_market=国内和欧洲") {
+		t.Errorf("missing target_market in prompt snippet: %s", snippet)
+	}
+}
diff --git a/internal/ctxmgr/window.go b/internal/ctxmgr/window.go
new file mode 100644
index 00000000..11b5e590
--- /dev/null
+++ b/internal/ctxmgr/window.go
@@ -0,0 +1,108 @@
+package ctxmgr
+
+import (
+	"fmt"
+	"strings"
+)
+
+// WindowConfig 滑动窗口配置
+type WindowConfig struct {
+	MaxTurns    int // 窗口内最大消息条数（一问一答计 2 条），默认 16
+	TokenBudget int // 窗口内字符/Token 预算，默认 3000
+	ReserveTail int // 为本轮用户输入与固定 Prompt 预留的字符预算，默认 800
+}
+
+// DefaultWindowConfig 返回默认滑动窗口配置
+func DefaultWindowConfig() WindowConfig {
+	return WindowConfig{
+		MaxTurns:    16,
+		TokenBudget: 3000,
+		ReserveTail: 800,
+	}
+}
+
+// EstimateTokens 估算文本 Token 数 (中文及中英混排场景下采用保守 rune 计数：1 rune ≈ 1 token)
+func EstimateTokens(s string) int {
+	return len([]rune(s))
+}
+
+// AssembleWindow 从完整历史消息列表中按双预算（条数上限 + Token预算）逆序裁剪出近期对话窗口
+// 返回：
+//   - window: 窗口内的近期消息（按原始时间正序）
+//   - early: 窗口之外被淘汰的早期消息（供滚动摘要器提取与压缩）
+//   - truncated: 是否发生了截断
+func AssembleWindow(msgs []ChatMessageRecord, cfg WindowConfig) (window []ChatMessageRecord, early []ChatMessageRecord, truncated bool) {
+	if len(msgs) == 0 {
+		return []ChatMessageRecord{}, []ChatMessageRecord{}, false
+	}
+
+	if cfg.MaxTurns <= 0 {
+		cfg.MaxTurns = 16
+	}
+	if cfg.TokenBudget <= 0 {
+		cfg.TokenBudget = 3000
+	}
+
+	netBudget := cfg.TokenBudget - cfg.ReserveTail
+	if netBudget < 400 {
+		netBudget = cfg.TokenBudget // 若预留过大，以全额预算为准
+	}
+
+	totalTokens := 0
+	cutIndex := 0
+
+	// 逆序向前收纳
+	for i := len(msgs) - 1; i >= 0; i-- {
+		m := msgs[i]
+		tokens := EstimateTokens(m.Content)
+		if tokens == 0 {
+			tokens = 1
+		}
+
+		// 检查条数预算与 Token 预算
+		countInWindow := len(msgs) - i
+		if countInWindow > cfg.MaxTurns || (totalTokens+tokens > netBudget && countInWindow > 2) {
+			cutIndex = i + 1
+			break
+		}
+
+		totalTokens += tokens
+	}
+
+	if cutIndex > 0 {
+		early = make([]ChatMessageRecord, cutIndex)
+		copy(early, msgs[:cutIndex])
+		window = make([]ChatMessageRecord, len(msgs)-cutIndex)
+		copy(window, msgs[cutIndex:])
+		return window, early, true
+	}
+
+	window = make([]ChatMessageRecord, len(msgs))
+	copy(window, msgs)
+	return window, []ChatMessageRecord{}, false
+}
+
+// FormatNumberedDialogue 将消息序列格式化为带逐轮序号的近期对话文本
+// 格式如：
+// [1] 用户: 帮我看看项目进展
+// [2] 助手: 当前处于 V0.1 阶段...
+func FormatNumberedDialogue(msgs []ChatMessageRecord, startIndex int) string {
+	if len(msgs) == 0 {
+		return ""
+	}
+	if startIndex <= 0 {
+		startIndex = 1
+	}
+
+	var sb strings.Builder
+	for i, m := range msgs {
+		roleName := "用户"
+		if m.Role == "assistant" {
+			roleName = "助手"
+		} else if m.Role == "system" {
+			roleName = "系统"
+		}
+		sb.WriteString(fmt.Sprintf("[%d] %s: %s\n", startIndex+i, roleName, strings.TrimSpace(m.Content)))
+	}
+	return sb.String()
+}
diff --git a/internal/ctxmgr/window_test.go b/internal/ctxmgr/window_test.go
new file mode 100644
index 00000000..b9b8f33e
--- /dev/null
+++ b/internal/ctxmgr/window_test.go
@@ -0,0 +1,90 @@
+package ctxmgr
+
+import (
+	"fmt"
+	"strings"
+	"testing"
+)
+
+func TestAssembleWindow_MaxTurnsBudget(t *testing.T) {
+	// 构造 20 条消息
+	var msgs []ChatMessageRecord
+	for i := 1; i <= 20; i++ {
+		role := "user"
+		if i%2 == 0 {
+			role = "assistant"
+		}
+		msgs = append(msgs, ChatMessageRecord{
+			ID:      int64(i),
+			Role:    role,
+			Content: fmt.Sprintf("这是测试消息第 %d 条内容", i),
+		})
+	}
+
+	cfg := WindowConfig{
+		MaxTurns:    8, // 最多 8 条
+		TokenBudget: 5000,
+		ReserveTail: 500,
+	}
+
+	window, early, truncated := AssembleWindow(msgs, cfg)
+	if !truncated {
+		t.Fatalf("expected truncated to be true")
+	}
+	if len(window) != 8 {
+		t.Errorf("expected 8 messages in window, got %d", len(window))
+	}
+	if len(early) != 12 {
+		t.Errorf("expected 12 messages in early, got %d", len(early))
+	}
+	// 检查窗口中第一条是否是第 13 条
+	if window[0].ID != 13 {
+		t.Errorf("expected window start with ID 13, got %d", window[0].ID)
+	}
+	// 检查窗口最后一条是否是第 20 条
+	if window[len(window)-1].ID != 20 {
+		t.Errorf("expected window end with ID 20, got %d", window[len(window)-1].ID)
+	}
+}
+
+func TestAssembleWindow_TokenBudgetLimit(t *testing.T) {
+	// 构造 5 条消息，每条内容长度 350 字符
+	var msgs []ChatMessageRecord
+	for i := 1; i <= 5; i++ {
+		msgs = append(msgs, ChatMessageRecord{
+			ID:      int64(i),
+			Role:    "user",
+			Content: strings.Repeat("长文本七字内容", 50), // 7 * 50 = 350 字符
+		})
+	}
+
+	cfg := WindowConfig{
+		MaxTurns:    10,   // 条数未超限
+		TokenBudget: 1000, // 预算 1000
+		ReserveTail: 200,  // 净可用 800，最多容纳 2 条 (300*2=600 <= 800)
+	}
+
+	window, early, truncated := AssembleWindow(msgs, cfg)
+	if !truncated {
+		t.Fatalf("expected truncated to be true")
+	}
+	if len(window) != 2 {
+		t.Errorf("expected 2 messages in window due to token budget, got %d", len(window))
+	}
+	if len(early) != 3 {
+		t.Errorf("expected 3 early messages, got %d", len(early))
+	}
+}
+
+func TestFormatNumberedDialogue(t *testing.T) {
+	msgs := []ChatMessageRecord{
+		{Role: "user", Content: "你好，请问你是谁？"},
+		{Role: "assistant", Content: "我是水木东方研发协同参谋。"},
+	}
+
+	formatted := FormatNumberedDialogue(msgs, 5)
+	expected := "[5] 用户: 你好，请问你是谁？\n[6] 助手: 我是水木东方研发协同参谋。\n"
+	if formatted != expected {
+		t.Errorf("expected formatted output:\n%s\ngot:\n%s", expected, formatted)
+	}
+}