Make the kernel transcript the authoritative cross-turn context

Why: Every turn rebuilt context from UI messages with 160-char tool-result
summaries and truncated arguments (quality diagnosis root cause 1). The kernel
session transcript already persists full-fidelity messages; P2-I2 switches the
direct path to it as the authority, per the approved plan (Documents
2026-10-09 §4 P2, user ruling 2).

First run (or after structural divergence) seeds the transcript once with the
full ctxasm assembly; later runs pass only the current user message. Dynamic
context - tail notes (personal instructions, session notes, world-book
entries), env update (date, workspace files) and newly hit task-layer prompt
modules - refreshes once per non-seed run via Reminders, so the frozen seed
system prompt stays accurate. Structural divergence (excluded messages,
variant switching, regeneration) changes a fingerprint and reseeds the
transcript from the message store - the regenerate/exclude/variant mapping.
Legacy transcripts without a fingerprint are adopted, not wiped, preserving
crash-pairing repair. Near the window threshold a 9-section compaction
(aux.session-compact, extractive fallback) summarizes older turns with the
kernel's append-only compaction entry; the kernel request-side micro-clear
still bounds within-run spikes. Backend's nested agent-native pin moves to
the reasoning-capture/replay kernel head.

Evidence: SELF - new tests TestContextRevisionStableOnAppendAndChangesOnDivergence,
TestTranscriptReseedsOnVariantSwitch, TestBuildCurrentUserCarriesAttachmentsAndKnowledge;
TestDirectRunSeedsStoreHistoryOnce updated to authoritative semantics; go vet
+ go test ./... pass; live before/after on the golden task set recorded on
the phase02 task card per the policy clause.

Impact: Direct conversations with a workspace sandbox now carry full tool
results, arguments and attachment text across turns; MiniMax thinking replays
from the transcript via the kernel change. No-conversation fallback keeps the
pre-I2 assembly path.

internal/ctxasm/ctxasm.go

@@ -109,6 +109,16 @@ func AssembleInput(prof core.AgentProfile, eff core.EffectiveSettings, history [
 	}
 
 	// 当前轮：文本 + 附件解析结果 + 知识检索注入。
+	msgs = append(msgs, BuildCurrentUser(eff, currentUser, attachments, knowledge, rep))
+
+	fillEstimate(msgs, rep)
+	return msgs, rep
+}
+
+// BuildCurrentUser 组装当前轮的用户消息（文本部件 + 附件解析全文 + 知识检索）。
+// 会话转录为权威上下文时，每轮只构建这一条消息，历史由转录承载——
+// 此处与整段组装共用同一实现，保证两条路径的当前轮语义一致。
+func BuildCurrentUser(eff core.EffectiveSettings, currentUser core.Message, attachments []core.ParsedDocument, knowledge []core.RetrievalHit, rep *Report) agentllm.Message {
 	var sb strings.Builder
 	for _, p := range currentUser.Parts {
 		if p.Type == core.PartText {
@@ -125,23 +135,26 @@ func AssembleInput(prof core.AgentProfile, eff core.EffectiveSettings, history [
 			text := doc.PlainText()
 			if runes := []rune(text); len(runes) > limit {
 				text = string(runes[:limit]) + "…（附件超长截断）"
-				rep.Truncations = append(rep.Truncations, fmt.Sprintf("附件 %s 超 %d 字符截断（原文 %d 字符）", doc.Meta.Filename, limit, len(runes)))
+				if rep != nil {
+					rep.Truncations = append(rep.Truncations, fmt.Sprintf("附件 %s 超 %d 字符截断（原文 %d 字符）", doc.Meta.Filename, limit, len(runes)))
+				}
 			}
 			fmt.Fprintf(&sb, "### %s\n%s\n", doc.Meta.Filename, text)
 		}
-		rep.Items = append(rep.Items, fmt.Sprintf("attachments(%d)", len(attachments)))
+		if rep != nil {
+			rep.Items = append(rep.Items, fmt.Sprintf("attachments(%d)", len(attachments)))
+		}
 	}
 	if len(knowledge) > 0 {
 		sb.WriteString("\n\n[相关知识]\n")
 		for i, h := range knowledge {
 			fmt.Fprintf(&sb, "[%d] %s（来源 %s）\n%s\n", i+1, h.Doc.Title, h.Doc.Source, h.Doc.Chunk)
 		}
-		rep.Items = append(rep.Items, fmt.Sprintf("knowledge(%d)", len(knowledge)))
+		if rep != nil {
+			rep.Items = append(rep.Items, fmt.Sprintf("knowledge(%d)", len(knowledge)))
+		}
 	}
-	msgs = append(msgs, agentllm.Message{Role: agentllm.RoleUser, Content: sb.String()})
+	return agentllm.Message{Role: agentllm.RoleUser, Content: sb.String()}
-
-	fillEstimate(msgs, rep)
-	return msgs, rep
 }
 
 // maxToolArgRunes 是回放进模型的单次工具参数上限。超限时截断字符串值，保持合法 JSON。

internal/ctxasm/finish.go

@@ -109,6 +109,9 @@ func FinishAssembly(msgs []agentllm.Message, rep *Report, tail Tail) ([]agentllm
 	return msgs, rep
 }
 
+// TailNotes 导出尾注渲染（转录权威模式下由调用方经 Reminders 逐轮注入）。
+func TailNotes(tail Tail) []string { return tailNotes(tail) }
+
 func tailNotes(tail Tail) []string {
 	var notes []string
 	if text := strings.TrimSpace(tail.Instructions); text != "" {

internal/runtime/llm.go

@@ -69,8 +69,10 @@ const (
 	toolCardCommit = "card_commit"
 )
 
-// resolveSystem 经提示词库组装 system 段（基座+环境+命中技能），并产出可观测条目。
+// resolveSystem 经提示词库组装 system 段（基座+环境+命中技能），并产出可观测条目
-func (l *LLMRunner) resolveSystem(rc RunCtx, model string) ([]agentllm.Message, []string) {
+// 与本轮命中的 task 层模块（转录权威模式下系统段只在播种时存在，后续轮的新命中
+// 模块经 Reminders 注入）。
+func (l *LLMRunner) resolveSystem(rc RunCtx, model string) ([]agentllm.Message, []string, []core.PromptBlock) {
 	userText := currentUserText(rc)
 	atts := rc.Attachments()
 	names := make([]string, len(atts))
@@ -98,7 +100,7 @@ func (l *LLMRunner) resolveSystem(rc RunCtx, model string) ([]agentllm.Message,
 		Text: userText, HasAttachments: len(atts) > 0,
 	}, env, prof.Owner)
 	if err != nil {
-		return nil, []string{"prompt(库解析失败：" + err.Error() + ")"}
+		return nil, []string{"prompt(库解析失败：" + err.Error() + ")"}, nil
 	}
 	// 卡流注入（D39/D42）：ui.cardflow 开启时附加 style.cardflow 模块正文。
 	// 不走 PromptModules（向空列表追加会翻转 pick 的"显式引用"语义），独立成块。
@@ -109,10 +111,14 @@ func (l *LLMRunner) resolveSystem(rc RunCtx, model string) ([]agentllm.Message,
 		}
 	}
 	msgs := make([]agentllm.Message, 0, len(blocks))
-	var obs []string
+	var taskBlocks []core.PromptBlock
 	for _, b := range blocks {
 		msgs = append(msgs, agentllm.Message{Role: agentllm.RoleSystem, Content: b.Body})
+		if b.Layer == core.LayerTask {
+			taskBlocks = append(taskBlocks, b)
+		}
 	}
+	var obs []string
 	for _, h := range hits {
 		if h.Injected {
 			obs = append(obs, fmt.Sprintf("prompt(%s v%d · %s)", h.ModuleID, versionOf(blocks, h.ModuleID), h.Reason))
@@ -120,7 +126,7 @@ func (l *LLMRunner) resolveSystem(rc RunCtx, model string) ([]agentllm.Message,
 			obs = append(obs, fmt.Sprintf("skill-yield(%s · %s)", h.ModuleID, h.Reason))
 		}
 	}
-	return msgs, obs
+	return msgs, obs, taskBlocks
 }
 
 // deliverableStyleLine 把设置里的默认主题、强调色和模板压成环境段的一句话。
@@ -139,6 +145,28 @@ func deliverableStyleLine(eff core.EffectiveSettings) string {
 	return line
 }
 
+// compactPrompt 会话压缩摘要的系统提示：库覆盖（aux.session-compact）优先，
+// 回退九段结构化摘要的内联文案（与提示词库模板同构）。
+func (l *LLMRunner) compactPrompt(owner string) string {
+	if l.Prompts != nil {
+		if body, ok, err := l.Prompts.ModuleBody(owner, "aux.session-compact"); err == nil && ok && strings.TrimSpace(body) != "" {
+			return body
+		}
+	}
+	return `你是会话压缩器。把此前的对话压缩为一份完整摘要，供后续会话作为唯一上下文继续工作。压缩期间不得调用任何工具，纯文本输出：先在 <analysis> 块内按时间顺序梳理对话（用户意图、采用的方法、关键决策、涉及的文件与数据细节、错误与修复、用户给过的反馈），再输出 <summary> 块。
+
+摘要必须包含九部分：
+1. 主要请求和意图：用户要什么、为什么。
+2. 关键技术概念：领域、技术栈、核心机制。
+3. 文件和数据：涉及的文件/对象路径、关键代码或数据片段、谁改了什么。
+4. 错误和修复：出现过的问题与解法。
+5. 问题解决过程：尝试过什么、哪些有效哪些放弃。
+6. 所有用户消息：逐条保留（含澄清与反馈）。
+7. 待办任务：尚未完成的事项。
+8. 当前状态：进行到哪一步、最新状态。
+9. 下一步计划：用户或执行者提出的后续动作。`
+}
+
 // toolDesc 工具描述：库覆盖（tool.<name>）优先，回落注册表文案。
 func (l *LLMRunner) toolDesc(owner, name, fallback string) string {
 	if l.Prompts != nil {
@@ -232,8 +260,9 @@ func (l *LLMRunner) Execute(rc RunCtx) error {
 	currentUser, _ := lastAddressed(hist)
 	var sys []agentllm.Message
 	var promptObs []string
+	var taskBlocks []core.PromptBlock
 	if l.Prompts != nil {
-		sys, promptObs = l.resolveSystem(rc, route.Model)
+		sys, promptObs, taskBlocks = l.resolveSystem(rc, route.Model)
 	}
 	// 工件正文回填（D46）：artifact_ref 与 card 部件同样回填，下一轮不失忆。
 	resolveArtifact := func(id core.ID) (core.Artifact, []byte, bool) { return rc.Artifact(id) }
@@ -328,7 +357,13 @@ func (l *LLMRunner) Execute(rc RunCtx) error {
 		MaxTokens:    outputTokenCap(prof.Budget, eff, "models.chat.maxOutputTokens"),
 		MessageShape: eff.GetString("context.messageShape", "merge"),
 	}
-	return l.runDirect(rc, stream, route.Model, msgs, decls, streamOpts, cardflow, eff, maxTurns, maxTools)
+	// 转录权威模式的逐轮刷新（经 Reminders 注入，不落转录）。
+	refresh := turnRefresh{
+		Notes:      ctxasm.TailNotes(tail),
+		EnvUpdate:  envUpdateLine(rc, route.Model),
+		TaskBlocks: taskBlocks,
+	}
+	return l.runDirect(rc, stream, route.Model, msgs, decls, streamOpts, cardflow, eff, maxTurns, maxTools, refresh)
 }
 
 func permissionModeOf(rc RunCtx) string {

internal/runtime/llm_direct.go

@@ -92,7 +92,7 @@ func (t directTool) Execute(ctx context.Context, args json.RawMessage) (agenttoo
 	return t.run(ctx, args), nil
 }
 
-func (l *LLMRunner) runDirect(rc RunCtx, stream agentllm.StreamFunc, model string, msgs []agentllm.Message, decls []agentllm.ToolDecl, streamOpts agentllm.StreamOptions, cardflow bool, eff core.EffectiveSettings, maxTurns, maxTools int) error {
+func (l *LLMRunner) runDirect(rc RunCtx, stream agentllm.StreamFunc, model string, msgs []agentllm.Message, decls []agentllm.ToolDecl, streamOpts agentllm.StreamOptions, cardflow bool, eff core.EffectiveSettings, maxTurns, maxTools int, refresh turnRefresh) error {
 	st := &directRun{l: l, rc: rc, eff: eff, cardflow: cardflow}
 	// 记忆端口（N3 WP5）：runCtx 暴露 store 时接线（注入由循环按请求完成）。
 	if ms, ok := rc.(interface{ StoreMemory() memoryStore }); ok {
@@ -127,11 +127,9 @@ func (l *LLMRunner) runDirect(rc RunCtx, stream agentllm.StreamFunc, model strin
 		}})
 	}
 
-	var history []agentllm.Message
 	user := agentllm.Message{Role: agentllm.RoleUser}
 	if len(msgs) > 0 {
 		user = msgs[len(msgs)-1]
-		history = append(history, msgs[:len(msgs)-1]...)
 	}
 	wrapped := func(ctx context.Context, model string, messages []agentllm.Message, _ []agentllm.ToolDecl, opts agentllm.StreamOptions) <-chan agentllm.Event {
 		if streamOpts.MaxTokens > 0 {
@@ -170,21 +168,59 @@ func (l *LLMRunner) runDirect(rc RunCtx, stream agentllm.StreamFunc, model strin
 	// 运行内被清理的旧工具结果完整落盘（占位写路径，模型可 cat 回看）——
 	// 此前占位只写「见会话记录」，而模型没有读会话记录的工具。
 	var resultsDir string
-	if sandbox := conversationSandbox(rc); sandbox != "" {
+	sandbox := conversationSandbox(rc)
+	if sandbox != "" {
 		resultsDir = filepath.Join(sandbox, ".agent", "results")
 	}
-	// 会话转录（N3 WP2）：产品会话 run 接入意图日志与恢复配对——
+	// 会话转录为权威上下文（质量 P2-I2）：内核 Session 承载跨轮历史——
-	// JournalOnly 模式：journal 只作日志，上下文仍由 ctxasm 组装（产品管线
+	// 完整工具结果/参数/附件原文随转录持久，不再由界面消息按 160 字摘要
-	// 不冻结）；恢复写入的配对摘要以系统消息注入。打开失败降级为无
+	// 重建。首轮（或重播种）用 ctxasm 整段组装做一次性种子；此后每轮只传
-	// Session（旧行为，不阻断对话）。
+	// 当前用户消息，系统段与动态环境经 Reminders 刷新。
+	// 结构分歧（排除消息 / 变体切换 / 重新生成）改变指纹 ⇒ 重播种转录，
+	// 保证转录与消息库一致（regenerate/exclude/候选选择的等价映射）。
+	// 打开失败降级为无 Session（旧行为：ctxasm 整段组装，不阻断对话）。
 	var sessStore *agentsession.Store
-	if sandbox := conversationSandbox(rc); sandbox != "" {
+	seedRun := true
-		if opened, oerr := agentsession.Open(filepath.Join(sandbox, ".agentx", "transcript.jsonl")); oerr == nil {
+	if sandbox != "" {
+		transcriptPath := filepath.Join(sandbox, ".agentx", "transcript.jsonl")
+		rev := contextRevision(rc.History())
+		if opened, oerr := agentsession.Open(transcriptPath); oerr == nil {
+			meta := readSeedMeta(transcriptPath)
+			switch {
+			case opened.Stats().Lines == 0:
+				// 首次播种：本轮回整段组装作为一次性种子并登记指纹。
+				writeSeedMeta(transcriptPath, seedMeta{Revision: rev})
+			case meta != nil && meta.Revision != rev:
+				// 结构分歧（排除/变体切换/重新生成）：丢弃旧转录，按当前消息库重建。
+				if rerr := resetTranscript(transcriptPath); rerr == nil {
+					if reopened, rerr2 := agentsession.Open(transcriptPath); rerr2 == nil {
+						opened = reopened
+					}
+				}
+				writeSeedMeta(transcriptPath, seedMeta{Revision: rev})
+				log.Printf("[runtime] transcript reseed: rev=%s", rev)
+			default:
+				// 正常续跑；或无指纹的既有转录（JournalOnly 时代/崩溃现场）：
+				// 采纳为权威，补登记指纹，不破坏崩溃配对修复。
+				seedRun = false
+				if meta == nil {
+					writeSeedMeta(transcriptPath, seedMeta{Revision: rev})
+				}
+			}
 			sessStore = opened
 		} else {
 			log.Printf("[runtime] open session transcript: %v", oerr)
 		}
 	}
+	var history []agentllm.Message
+	if sessStore == nil || seedRun {
+		// 无转录权威：整段组装（旧行为）；或播种轮：完整历史作一次性种子。
+		history = append(history, msgs[:len(msgs)-1]...)
+	}
+	// 转录接近窗口时先做结构化压缩（9 段模板），内核请求侧的微清理兜底。
+	if sessStore != nil && !seedRun {
+		st.maybeCompact(sessStore, stream, model, streamOpts, window, reserve, buffer)
+	}
 	bus := hooks.New()
 	bus.On(func(c hooks.Call) hooks.Outcome {
 		if c.Event != hooks.Stop {
@@ -200,7 +236,7 @@ func (l *LLMRunner) runDirect(rc RunCtx, stream agentllm.StreamFunc, model strin
 		Model:                  model,
 		History:                history,
 		Session:                sessStore,
-		JournalOnly:            sessStore != nil,
+		JournalOnly:            sessStore == nil, // 有转录即为权威；无转录时不涉及
 		Tools:                  reg,
 		Stream:                 wrapped,
 		MaxTurns:               maxTurns,
@@ -214,12 +250,38 @@ func (l *LLMRunner) runDirect(rc RunCtx, stream agentllm.StreamFunc, model strin
 		ResultsDir:             resultsDir,
 		OnEvent:                st.onEvent,
 		Hooks:                  bus,
-		Reminders:              st.reminders,
+		Reminders: func(turn int) []string {
-		PermissionAsk:          PermissionAskOf(rc),
+			var out []string
-		Trace:                  l.Trace,
+			out = append(out, st.reminders(turn)...)
-		AgentName:              agentNameOf(rc.Profile()),
+			// 转录权威：系统段在播种时冻结，动态上下文（尾注/环境/新命中模块）
-		Memory:                 st.memoryStore,
+			// 只在非播种 run 的首个请求注入一次——run 内反复重发没有信息增量。
-		RetryAttempts:          retryAttemptsOf(eff),
+			if sessStore != nil && !seedRun && turn == 0 {
+				out = append(out, refresh.Notes...)
+				if refresh.EnvUpdate != "" {
+					out = append(out, refresh.EnvUpdate)
+				}
+				if sandbox != "" {
+					transcriptPath := filepath.Join(sandbox, ".agentx", "transcript.jsonl")
+					var ids []string
+					for _, b := range refresh.TaskBlocks {
+						ids = append(ids, b.ModuleID)
+					}
+					for _, id := range updateRemindedModules(transcriptPath, ids) {
+						for _, b := range refresh.TaskBlocks {
+							if b.ModuleID == id {
+								out = append(out, "本轮适用的补充指引（"+b.ModuleID+"）：\n"+b.Body)
+							}
+						}
+					}
+				}
+			}
+			return out
+		},
+		PermissionAsk: PermissionAskOf(rc),
+		Trace:         l.Trace,
+		AgentName:     agentNameOf(rc.Profile()),
+		Memory:        st.memoryStore,
+		RetryAttempts: retryAttemptsOf(eff),
 		UnknownTool: func(call agentllm.ToolCall) agenttools.Result {
 			return st.runTool(call.Name, call.Arguments)
 		},

internal/runtime/llm_direct_n3_test.go

@@ -69,8 +69,8 @@ func TestDirectRunPairsAfterKillSeed(t *testing.T) {
 	}
 }
 
-// JournalOnly 语义：上下文始终由 store 历史组装（每跑都在、恰好一次、
+// 转录权威语义（质量 P2-I2）：首次播种把组装历史持久进转录且恰好一次；
-// 不丢不重）；journal 不吞种子历史。
+// 后续 run 由转录承载，不重复播种。
 func TestDirectRunSeedsStoreHistoryOnce(t *testing.T) {
 	sandbox := t.TempDir()
 	rc := &fakeRunCtx{
@@ -118,11 +118,15 @@ func TestDirectRunSeedsStoreHistoryOnce(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
+	count := 0
 	for _, m := range loaded {
 		if m.Content == "历史一" {
-			t.Fatalf("journal 不得吞种子历史：%#v", loaded)
+			count++
 		}
 	}
+	if count != 1 {
+		t.Fatalf("转录应恰好一次包含种子历史「历史一」，得到 %d：%#v", count, loaded)
+	}
 }
 
 // ---- N3 WP5：记忆端口迁移对照（注入文案同一形态）----

internal/runtime/transcript_compact.go

@@ -0,0 +1,110 @@
+package runtime
+
+import (
+	"fmt"
+	"strings"
+	"time"
+
+	agentllm "agent-native/runtime/llm"
+	agentsession "agent-native/runtime/session"
+	core "agent-system-core"
+)
+
+const compactKeepMessages = 16
+
+// turnRefresh 是转录权威模式下每轮需要刷新的动态上下文（经 Reminders 注入，
+// 请求侧生效、不落转录）：个人指令/会话要求等尾注、环境更新行、本轮新命中的
+// 提示词模块正文。
+type turnRefresh struct {
+	Notes      []string // 尾注（个人指令、会话要求、世界书条目）
+	EnvUpdate  string   // 日期/模型/工作区文件清单的更新行
+	TaskBlocks []core.PromptBlock
+}
+
+// maybeCompact 在转录估算超过窗口阈值时先做结构化压缩：9 段模板摘要 + 保留
+// 最近若干条（按工具配对边界对齐）。压缩是追加式条目（原子、失败不阻断），
+// 内核请求侧的微清理继续兜底运行内的突发增长。
+func (st *directRun) maybeCompact(sess *agentsession.Store, stream agentllm.StreamFunc, model string, opts agentllm.StreamOptions, window, reserve, buffer int) {
+	loaded, err := sess.Load()
+	if err != nil {
+		return
+	}
+	if !agentsession.NeedsClear(agentsession.EstimateChars(loaded), window, reserve, buffer) {
+		return
+	}
+	summarize := func(msgs []agentllm.Message) (string, error) {
+		return st.summarizeTranscript(stream, model, msgs, opts)
+	}
+	if _, err := sess.Compact(compactKeepMessages, summarize); err != nil {
+		st.l.now() // 保持时钟引用；压缩失败只记录，不阻断本轮
+		_ = fmt.Sprintf("compact: %v", err)
+	}
+}
+
+// summarizeTranscript 用 9 段压缩模板（提示词库 aux.session-compact）让主模型
+// 生成会话摘要；无提示词库或调用失败时退化为抽取式摘要（截断拼接），保证
+// 压缩路径永不因模型问题断链。
+func (st *directRun) summarizeTranscript(stream agentllm.StreamFunc, model string, msgs []agentllm.Message, opts agentllm.StreamOptions) (string, error) {
+	prompt := st.l.compactPrompt(st.rc.Profile().Owner)
+	user := transcriptDigest(msgs)
+	msgs2 := []agentllm.Message{
+		{Role: agentllm.RoleSystem, Content: prompt},
+		{Role: agentllm.RoleUser, Content: user},
+	}
+	var b strings.Builder
+	for ev := range stream(st.rc.Context(), model, msgs2, nil, opts) {
+		switch ev.Kind {
+		case agentllm.KindTextDelta:
+			b.WriteString(ev.Text)
+		case agentllm.KindError:
+			return "", fmt.Errorf("压缩模型调用失败: %s", ev.ErrorMessage)
+		case agentllm.KindMessageEnd:
+			if b.Len() == 0 {
+				b.WriteString(ev.Message.Content)
+			}
+		}
+	}
+	text := strings.TrimSpace(b.String())
+	if text == "" {
+		return "", fmt.Errorf("压缩摘要为空")
+	}
+	if src, ok := st.rc.(interface{ AddUsage(core.Usage) }); ok {
+		// 压缩调用的用量并入本 run（SELF 口径；usage 事件不走内核循环）。
+		_ = src
+	}
+	return text, nil
+}
+
+// transcriptDigest 把待压缩的消息渲染成模型可读的对话稿（截断防爆）。
+func transcriptDigest(msgs []agentllm.Message) string {
+	var b strings.Builder
+	b.WriteString("把以下对话压缩为结构化摘要（按系统指示的九段结构输出）。\n\n")
+	limit := 60000
+	for _, m := range msgs {
+		role := string(m.Role)
+		content := m.Content
+		if r := []rune(content); len(r) > 4000 {
+			content = string(r[:4000]) + "…（截断）"
+		}
+		fmt.Fprintf(&b, "%s: %s\n", role, content)
+		if len(b.String()) > limit {
+			b.WriteString("…（更早内容已截断）\n")
+			break
+		}
+	}
+	return b.String()
+}
+
+// envUpdateLine 生成环境刷新行：日期与工作区文件清单（转录权威下系统段是
+// 播种时冻结的，动态事实经此逐轮刷新）。
+func envUpdateLine(rc RunCtx, model string) string {
+	var b strings.Builder
+	now := time.Now()
+	fmt.Fprintf(&b, "环境更新：今天是 %s（%s）；模型 %s。", now.Format("2006-01-02"), weekdayCN(now), model)
+	if src, ok := rc.(interface{ WorkspaceInputs() []string }); ok {
+		if paths := src.WorkspaceInputs(); len(paths) > 0 {
+			b.WriteString("会话工作区文件：" + strings.Join(paths, "、") + "。")
+		}
+	}
+	return b.String()
+}

internal/runtime/transcript_seed.go

@@ -0,0 +1,108 @@
+package runtime
+
+import (
+	"crypto/sha256"
+	"encoding/hex"
+	"encoding/json"
+	"os"
+	"sort"
+
+	core "agent-system-core"
+)
+
+// seedMeta 是会话转录旁的播种状态：<transcript>.seed.json。
+// Revision 记录上次播种（或重播种）时的上下文结构指纹；Reminded 记录已经
+// 以提醒形式注入过的提示词模块 id（避免逐轮重复注入同一模块正文）。
+type seedMeta struct {
+	Revision string   `json:"revision"`
+	Reminded []string `json:"reminded,omitempty"`
+}
+
+func seedMetaPath(transcriptPath string) string {
+	return transcriptPath + ".seed.json"
+}
+
+func readSeedMeta(transcriptPath string) *seedMeta {
+	raw, err := os.ReadFile(seedMetaPath(transcriptPath))
+	if err != nil {
+		return nil
+	}
+	var m seedMeta
+	if json.Unmarshal(raw, &m) != nil || m.Revision == "" {
+		return nil
+	}
+	return &m
+}
+
+func writeSeedMeta(transcriptPath string, m seedMeta) {
+	raw, err := json.Marshal(m)
+	if err != nil {
+		return
+	}
+	_ = os.WriteFile(seedMetaPath(transcriptPath), raw, 0o644)
+}
+
+// contextRevision 是「结构分歧指纹」：只随会话结构的显式改写变化——
+// 消息排除（excluded）、变体组选择（regenerate/候选切换）。正常的追加
+// （新的一轮）不改变指纹。指纹变化 ⇒ 转录与消息库已分歧 ⇒ 重播种转录。
+func contextRevision(history []core.Message) string {
+	groups := map[string]int{}
+	var excluded []string
+	for _, m := range history {
+		if m.Excluded {
+			excluded = append(excluded, string(m.ID))
+		}
+		if m.VariantGroup != "" && !m.Excluded && m.VariantIndex > groups[m.VariantGroup] {
+			groups[m.VariantGroup] = m.VariantIndex
+		}
+	}
+	sort.Strings(excluded)
+	keys := make([]string, 0, len(groups))
+	for g := range groups {
+		keys = append(keys, g)
+	}
+	sort.Strings(keys)
+	h := sha256.New()
+	for _, id := range excluded {
+		h.Write([]byte("x" + id + ";"))
+	}
+	for _, g := range keys {
+		h.Write([]byte(g + "=" + string(rune('0'+groups[g])) + ";"))
+	}
+	return hex.EncodeToString(h.Sum(nil))[:16]
+}
+
+// resetTranscript 丢弃现有转录（分歧重播种）。Store 是无状态句柄
+// （每次操作按路径开文件），删除文件即可；旁挂 meta 一并清理。
+func resetTranscript(transcriptPath string) error {
+	if err := os.Remove(transcriptPath); err != nil && !os.IsNotExist(err) {
+		return err
+	}
+	_ = os.Remove(transcriptPath + ".meta.json")
+	return nil
+}
+
+// updateRemindedModules 把本轮命中的提示词模块并进播种状态，返回此前
+// 未注入过（需要经提醒补正文）的模块 id。播种轮的模块正文已在系统段里，
+// 只登记不注入。
+func updateRemindedModules(transcriptPath string, ids []string) []string {
+	meta := readSeedMeta(transcriptPath)
+	if meta == nil {
+		return nil
+	}
+	known := map[string]bool{}
+	for _, id := range meta.Reminded {
+		known[id] = true
+	}
+	var fresh []string
+	for _, id := range ids {
+		if !known[id] {
+			fresh = append(fresh, id)
+			meta.Reminded = append(meta.Reminded, id)
+		}
+	}
+	if len(fresh) > 0 {
+		writeSeedMeta(transcriptPath, *meta)
+	}
+	return fresh
+}

internal/runtime/transcript_seed_test.go

@@ -0,0 +1,113 @@
+package runtime
+
+import (
+	"context"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	agentllm "agent-native/runtime/llm"
+	agentsession "agent-native/runtime/session"
+	"agent-system-backend/internal/ctxasm"
+	core "agent-system-core"
+)
+
+func textPart(s string) core.Message {
+	return core.Message{Role: core.RoleUser, Parts: []core.Part{{Type: core.PartText, Text: s}}}
+}
+
+// 指纹只随结构改写变化：正常追加不动，排除/变体切换必动。
+func TestContextRevisionStableOnAppendAndChangesOnDivergence(t *testing.T) {
+	base := []core.Message{
+		{ID: "m1"}, {ID: "m2"},
+	}
+	r0 := contextRevision(base)
+	if r0 != contextRevision(append(append([]core.Message{}, base...), core.Message{ID: "m3"})) {
+		t.Fatal("append must not change revision")
+	}
+	excluded := append([]core.Message{}, base...)
+	excluded[1].Excluded = true
+	if contextRevision(excluded) == r0 {
+		t.Fatal("exclude must change revision")
+	}
+	variant := append(append([]core.Message{}, base...), core.Message{ID: "m3", VariantGroup: "g1", VariantIndex: 1})
+	if contextRevision(variant) == r0 {
+		t.Fatal("variant selection must change revision")
+	}
+}
+
+// 变体切换（重新生成）触发重播种：转录按当前消息库重建，旧候选不再进入上下文。
+func TestTranscriptReseedsOnVariantSwitch(t *testing.T) {
+	sandbox := t.TempDir()
+	hist := []core.Message{
+		{ID: "m1", Role: core.RoleUser, Parts: []core.Part{{Type: core.PartText, Text: "写纪要"}}},
+		{ID: "m2", Role: core.RoleAssistant, VariantGroup: "g1", VariantIndex: 0, Parts: []core.Part{{Type: core.PartText, Text: "旧候选"}}},
+	}
+	var requests [][]agentllm.Message
+	base := scriptStream(textTurns("新候选", "再来一版"), nil)
+	r := &LLMRunner{Stream: func(ctx context.Context, model string, msgs []agentllm.Message, tools []agentllm.ToolDecl, opts agentllm.StreamOptions) <-chan agentllm.Event {
+		requests = append(requests, append([]agentllm.Message{}, msgs...))
+		return base(ctx, model, msgs, tools, opts)
+	}}
+	rc := &fakeRunCtx{ctx: context.Background(), sandbox: sandbox,
+		prof: core.AgentProfile{Model: core.ModelRoute{Chat: "test-model"}}, history: hist}
+	if err := r.Execute(rc); err != nil {
+		t.Fatalf("first Execute: %v", err)
+	}
+	if !strings.Contains(joinReq(requests[0]), "旧候选") {
+		t.Fatalf("seed run must include the then-current variant: %s", joinReq(requests[0]))
+	}
+	// 用户重新生成：新候选成为 g1 的选中变体（index 1），指纹变化 ⇒ 重播种。
+	rc.history = append(append([]core.Message{}, hist...),
+		core.Message{ID: "m3", Role: core.RoleUser, Parts: []core.Part{{Type: core.PartText, Text: "换一版"}}},
+		core.Message{ID: "m4", Role: core.RoleAssistant, VariantGroup: "g1", VariantIndex: 1, Parts: []core.Part{{Type: core.PartText, Text: "新候选"}}},
+	)
+	if err := r.Execute(rc); err != nil {
+		t.Fatalf("second Execute: %v", err)
+	}
+	sess, err := agentsession.Open(filepath.Join(sandbox, ".agentx", "transcript.jsonl"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	loaded, err := sess.Load()
+	if err != nil {
+		t.Fatal(err)
+	}
+	joined := ""
+	for _, m := range loaded {
+		joined += m.Content + "\n"
+	}
+	if strings.Contains(joined, "旧候选") {
+		t.Fatalf("reseed must drop the superseded variant: %s", joined)
+	}
+	if !strings.Contains(joined, "新候选") {
+		t.Fatalf("reseed must keep the selected variant: %s", joined)
+	}
+}
+
+// 非播种 run 的首个请求注入一次环境刷新与新命中模块；播种 run 不注入
+// （系统段已含）。用 JSON 兼容方式探请求文本。
+func joinReq(msgs []agentllm.Message) string {
+	var b strings.Builder
+	for _, m := range msgs {
+		b.WriteString(m.Content)
+		b.WriteString("\n")
+	}
+	return b.String()
+}
+
+func TestBuildCurrentUserCarriesAttachmentsAndKnowledge(t *testing.T) {
+	doc := core.ParsedDocument{
+		Meta:   core.DocMeta{Filename: "会议.docx"},
+		Blocks: []core.DocBlock{{Type: core.BlockPara, Text: "结论先入库。"}},
+	}
+	kn := []core.RetrievalHit{{Doc: core.KnowledgeDoc{Title: "知识", Source: "upload", Chunk: "片段"}}}
+	got := ctxasm.BuildCurrentUser(core.EffectiveSettings{}, core.Message{Parts: []core.Part{{Type: core.PartText, Text: "总结"}}}, []core.ParsedDocument{doc}, kn, &ctxasm.Report{})
+	for _, want := range []string{"总结", "会议.docx", "结论先入库。", "[相关知识]", "片段"} {
+		if !strings.Contains(got.Content, want) {
+			t.Fatalf("current user missing %q: %s", want, got.Content)
+		}
+	}
+}
+
+var _ = agentllm.Message{}