diff --git a/.planning/2026-10-14-history-memory-fix/findings.md b/.planning/2026-10-14-history-memory-fix/findings.md
new file mode 100644
index 0000000..8a9128f
--- /dev/null
+++ b/.planning/2026-10-14-history-memory-fix/findings.md
@@ -0,0 +1,10 @@
+# 调查与实现依据
+
+- 现有完整历史库：lib/session-history-store.js。
+- server.js 的 loadSession、saveSession、resolveSessionHistory、refreshSessionSnapshotCache 接入归档。
+- 原有契约要求原子提交、可信加载、旧修订合并、删除及清空不复活、完整运行态优先恢复。
+- 不能把分块存储只做在文件层：分页入口和快照刷新也须避免整份加载。
+- 采用不可变内容哈希块与原子 manifest 提交；可信基线只保留块引用，旧修订按单消息逐字段合并。
+- 服务端常用加载保留有界尾部，分页直接读区间，任务跟踪只读元数据；明确导入/全量维护才申请完整加载。
+- 集成回归创建 `_history/_turns` 后发现保留目录触发无效会话ID错误；列表枚举须显式排除该目录和同名旧文件，34项持久化回归已覆盖。
+- 最终合成夹具：70.5MiB完整旧归档在256MiB堆上限下完成流式迁移、增量保存和67页读取，RSS峰值145.9MiB；1128条正文和工具数据逐条摘要相符。完整集成回归通过；运行服务尚未重启，生产内存效果须在修复生效后另行观察。
diff --git a/.planning/2026-10-14-history-memory-fix/progress.md b/.planning/2026-10-14-history-memory-fix/progress.md
new file mode 100644
index 0000000..a71232a
--- /dev/null
+++ b/.planning/2026-10-14-history-memory-fix/progress.md
@@ -0,0 +1,15 @@
+# 执行记录
+
+2026-10-14：初始化项目上下文，确认完整历史功能与归档库。用户要求继续推进修复。
+定位已完成，进入分块存储和服务端有界入口实现；测试代理负责隔离内存回归。未重启服务。
+
+分块清单、增量保存、64KiB流式迁移、默认尾部和首屏/重连/分页入口已实现。
+补齐元数据保存、单消息修改窗口、跨窗口查重和附件逐块遍历，避免尾部加载遗漏早期消息。
+首轮70.5MiB合成归档在256MiB堆上限下通过，RSS峰值144.6MiB；全部1128条消息逐条摘要相符。
+当前补齐默认窗口、并发和失败重试回归，并验证运行完成及自动重试路径。测试保持隔离目录，未重启生产服务。
+
+集成回归定位并修复 `_history/_turns` 保留目录被会话列表枚举的问题，补充真实运行态目录及同名旧文件回归。完整历史持久化单测34项全部通过，完整集成回归继续执行。
+
+最终验证：`TMPDIR=/dev/shm timeout 300s node scripts/regression.js` 退出0，输出 Regression checks passed；包含完整历史存储、内存、首屏/分页、运行完成、重启恢复及自动重试回归。最终单独内存回归退出0：70.5MiB旧归档、256MiB堆上限、RSS峰值145.9MiB，1128条消息经67页逐条校验完整，6次增量保存复用37个原始块，单次旧文件读取最多64KiB。该数字为合成隔离夹具，不能当作生产进程测量。语法检查和 git diff --check 通过。
+
+交付完成：所有计划步骤完成，临时TODO CSV已清理；源码与后端契约已更新，保留既有未提交文案改动及10-11任务。未修改生产历史，未打包、提交或重启服务，运行进程仍须后续安全重启后生效。
diff --git a/.planning/2026-10-14-history-memory-fix/task_plan.md b/.planning/2026-10-14-history-memory-fix/task_plan.md
new file mode 100644
index 0000000..eaa66ff
--- /dev/null
+++ b/.planning/2026-10-14-history-memory-fix/task_plan.md
@@ -0,0 +1,25 @@
+# 完整历史内存修复
+
+目标：保留完整会话历史，消除完整归档加载、保存和基线的整份复制，增加分块存储、按页读取和安全迁移。
+
+## 阶段
+1. 确认归档和分页入口，确定内存有界的实现：complete
+2. 实现分块归档、按页读取和旧数据迁移：complete
+3. 验证历史完整性、并发保护和内存峰值：complete
+4. 完成代码复核并交付验证结果：complete
+
+## 边界
+- 保留正文、工具参数和结果，不用截断历史换取内存。
+- 不覆盖现有 server.js 未提交改动。
+- 测试使用隔离目录，不修改生产归档。
+- 重启前必须确认没有其他运行中的对话。
+
+## 已知情况
+- 当前完整历史格式见 .trellis/spec/backend/session-history.md。
+- 用户要求继续推进，不再停留在审计流程。
+- 初始 git 状态：server.js 已修改；10-11-remove-compact-followup 为既有任务。
+
+## 问题记录
+- 首次定位 todo-list-csv 技能不存在，采用项目规定的 CSV 与 update_plan 同步。
+- Codebase Memory 部分命中位置错位，须用实际文件交叉校验。
+- 本轮 Codebase Memory 连接已关闭，改用 FastCtx 精确读文件继续实现。
diff --git a/.planning/2026-10-14-runtime-json-fix/findings.md b/.planning/2026-10-14-runtime-json-fix/findings.md
new file mode 100644
index 0000000..e0273a4
--- /dev/null
+++ b/.planning/2026-10-14-runtime-json-fix/findings.md
@@ -0,0 +1,9 @@
+# 实现依据
+
+- `saveTurn`仍通过`writeAtomicJson`整份序列化，`loadTurn`仍整文件读取并JSON.parse，是本轮补齐点。
+- `preserveNewerTaskTrackingForSessionSave`已只读元数据，但每次保存重复读清单，改为归档内部合并。
+- 历史基线已经是不可变块引用，不需要改回整文件磁盘基线。
+- 流式JSON实现固定64KiB字节缓冲，字符串按8Ki字符段转义并保护代理对；解析按容器和值构造对象，保留原v1运行态格式。旧归档迁移共用新解析器，移除重复扫描实现。
+- 任务状态保护使用同一次提交取得的当前清单；可信同修订保存仅读256字节修订头，保存后才同步受保护的任务状态，失败不推进会话与基线。
+- 最终隔离集成回归退出0；JSON10项、历史持久化38项通过。80MiB运行态在256MiB堆参数下RSS峰值210.5MiB，读写最大64KiB；重开正文摘要完整，write/fsync/rename失败保留旧档且无tmp残留。
+- 本轮仍未重启服务或修改生产历史。运行态返回完整对象，峰值随单条正文和同时存活运行态增长；测得RSS只代表合成夹具。
diff --git a/.planning/2026-10-14-runtime-json-fix/progress.md b/.planning/2026-10-14-runtime-json-fix/progress.md
new file mode 100644
index 0000000..868aa07
--- /dev/null
+++ b/.planning/2026-10-14-runtime-json-fix/progress.md
@@ -0,0 +1,15 @@
+# 执行记录
+
+2026-10-14：用户要求按另一实例方案继续修改；限定为运行态流式读写、结构比较及单次提交中的任务状态保护，保留分块归档设计。
+
+已实现通用流式JSON读写、仅容器克隆和结构比较，并接入完整运行态、原子清单写入及旧格式迁移。归档内部保护任务版本，同修订保存只读修订头。测试代理只新增JSON与大运行态回归，主代理补任务状态及失败边界。
+
+首次持久化回归发现新增修订头调用与提交修订局部变量同名，命中暂存区错误；局部变量改为nextRevision后重新验证，避免同修订快速路径失效。
+
+持久化回归38项通过，新增同修订零完整读取、并发任务版本、任务看板删除及失败不推进基线四类验证。JSON新测试10项通过；80MiB运行态在256MiB堆下读取和保存并注入写/fsync/rename失败，正文摘要完整、旧文件不变、无临时文件残留，RSS峰值210.1MiB、单次读写64KiB。继续完整集成回归。
+
+最终完整回归：`TMPDIR=/dev/shm timeout 300s node scripts/regression.js`退出0，输出Regression checks passed。进一步修复toJSON getter只读取一次并补断言，最终JSON回归10项及运行态内存回归均退出0；运行态80MiB、256MiB堆参数下RSS峰值210.5MiB，单次读写64KiB。lib/json-persistence.js、lib/session-history-store.js与server.js语法检查通过，git diff --check通过。文档已补充格式、失败语义和峰值局限。
+
+交付完成：最终测试日志与工作区状态已核对，全部计划项完成，移除临时CSV跟踪文件。保留历史分块归档和分页读取，未改写生产历史、未打包、未提交或重启服务；当前服务进程尚未加载本轮源码修改。
+
+后续交付：按用户要求使用本地Bun 1.4.2重新生成CentOS 7 baseline单文件发布包，目标为bun-linux-x64-baseline。规定的8个文件语法检查及git diff --check通过；新二进制MCP initialize返回有效JSON-RPC结果并正常退出。压缩包138个归档项，二进制和前端资源与当前构建一致；大小42.91MiB，SHA-256为7bbe795e39f61fdc4e47d96a2083d92e9a2f59593e2e4c5397debdb67a84b7c9。提交范围包含工作区全部源码、回归脚本、文档、任务记录和更新后的发布包；未重启服务。
diff --git a/.planning/2026-10-14-runtime-json-fix/task_plan.md b/.planning/2026-10-14-runtime-json-fix/task_plan.md
new file mode 100644
index 0000000..bc6f9c9
--- /dev/null
+++ b/.planning/2026-10-14-runtime-json-fix/task_plan.md
@@ -0,0 +1,12 @@
+# 运行态流式持久化补齐
+
+目标：吸收另一实例的流式JSON读写和单次任务状态提交方案，同时保留当前分块归档、分页读取和清单基线。
+
+1. 确认运行态持久化和任务状态合并的现有契约：complete
+2. 实现流式JSON读写并整合任务状态保护：complete
+3. 验证JSON语义、失败保护及大运行态低堆回归：complete
+4. 更新契约与交付验证结果：complete
+
+边界：不覆盖此前已完成的历史分块实现和既有文案改动；不修改生产历史，不打包或重启服务；单测上限60秒。
+
+已知：Codebase Memory连接此前已关闭，源码使用FastCtx读取及rg精确校验；todo-list-csv技能不存在，按AGENTS维护CSV和update_plan。
diff --git a/.trellis/spec/backend/quality-guidelines.md b/.trellis/spec/backend/quality-guidelines.md
index 8777537..6b0c3b1 100644
--- a/.trellis/spec/backend/quality-guidelines.md
+++ b/.trellis/spec/backend/quality-guidelines.md
@@ -45,6 +45,8 @@ Questions to answer:
 - 完整档案先原子提交，随后更新有界快照；完整档案失败时不得用裁剪快照覆盖上次状态。档案提交成功而快照失败时，读取和会话列表仍须能找到已提交档案。
 - 可信完整读取后的修改应保留清空、撤回和插入顺序；短预览及旧修订不能覆盖完整消息或丢掉后来追加的记录，正常并发保存不得静默漏记。
 - 旧版截断历史只有在确认原始记录对应边界后才能补入完整档案；新建档案本身不能证明旧历史已完整。
+- 大型运行态JSON须使用分段编码和直接构造对象的流式读取，禁止完整原文、全量写出缓冲及序列化克隆同时驻留；不能把单次读写有界解释为返回对象总内存有界。
+- 任务状态版本保护在同一次归档提交内处理，失败不得提前推进可信基线或活跃任务状态；JSON读写需对照原生语义并覆盖跨段编码、短读短写及原子失败保护。
 
 ---
 
diff --git a/.trellis/spec/backend/session-history.md b/.trellis/spec/backend/session-history.md
index 94c11f3..f1c8b65 100644
--- a/.trellis/spec/backend/session-history.md
+++ b/.trellis/spec/backend/session-history.md
@@ -9,7 +9,15 @@
 ```js
 createSessionHistoryStore({ sessionsDir, fs? })
 store.load(id)                    // 完整会话或 null；注册可信加载基线
-store.save(session)               // { revision, complete, session, rebased }；失败抛错
+store.loadTail(id, count = 180, { maxBytes? }) // 只加载可修改尾部，保留全局索引
+store.loadMetadata(id)            // 只加载元数据，保存时保留全部消息
+store.loadWindow(id, start, end)  // 可修改中间窗口，保存时保留前缀和后缀
+store.loadHistoryPage(id, before, count = 24) // { messages, total, start, end, complete, revision }
+store.findMessage(id, predicate)  // 按块查找，内存只保留少量块
+store.forEachMessage(id, callback) // 按块遍历，用于附件清理等全历史操作
+store.messageIndex(id, messageId) // 从轻量清单查询全局消息索引
+store.countMessages(id, role)     // 从清单计数，不加载正文
+store.save(session, { taskBoardMetadata? }) // { revision, complete, session, rebased, taskTrackingPreserved }；失败抛错
 store.markLegacy(session)         // 注册旧快照来源与完整性状态
 store.markComplete(session, { reset? }) // 确认可靠补齐或主动清空；返回状态还原函数
 store.state(session)              // 来源、修订与完整性；不暴露消息基线
@@ -21,21 +29,26 @@ store.loadTurn(id)                // 优先于有界运行预览
 store.listTurnIds()
 store.removeTurn(id)              // 完整消息已提交或主动清空后才清理
 saveSession(session)              // 完整档案提交成功为 true，否则 false
-loadSession(id)                   // 优先完整档案；无档案才读取旧快照
-resolveSessionHistory(session)    // { messages, source, available, recoverable }
+loadSession(id, options?)         // 默认尾部最多180条、2MiB；单条超大消息完整保留
+// options 支持 metadata、count、window、messageId、promptId；显式 full 才全量加载
+resolveSessionHistory(session, { count?, before? }) // 有界出口另含 total/start/end
 ```
 
 ## 3. 存储与响应契约
 
-- `${SESSIONS_DIR}/_history/<id>.json` 是持久提交点，格式为 `{ version: 1, revision, complete, resetRevision, session }`。`session` 包含完整可序列化字段，排除运行态句柄；正文、工具、数组和深度不使用预览限额。
+- `${SESSIONS_DIR}/_history/<id>/manifest.json` 是唯一持久提交点，格式为 `{ version: 2, revision, complete, resetRevision, session, entries }`。`session` 只有可序列化元数据，排除运行态句柄；`entries` 只保留稳定消息 ID、角色、摘要、块引用、块内索引和字节数。
+- 完整消息保存在 `chunks/<sha256>.json` 不可变块中，默认每块最多 2 MiB 或 64 条；单条超大消息允许独占大块，正文、工具、数组和深度不使用预览限额。保存复用内容未变的块，只写修改的消息，不序列化或复制整份历史。
+- 旧 `_history/<id>.json` 首次读取时使用 `lib/json-persistence.js` 按 64 KiB 扫描流式迁移，每次构造一个字段或消息；块全部落盘后才提交新清单。旧文件保留，迁移失败不破坏原文件。
 - `<id>.json` 是有界快照缓存。`historyArchiveRevision` 位于顶层首字段，用来判断缓存是否过期；不得从嵌套同名键推断修订。
 - `CC_WEB_SESSION_PERSIST_MAX_MESSAGES`、`CC_WEB_SESSION_MESSAGE_CONTENT_MAX_CHARS` 等预览配置不能限制完整档案；真实完成和恢复路径也不得先裁剪消息再提交。
-- 可信来源保存在存储实例的 `WeakMap`，不能凭 JSON 的修订字段伪造。当前修订精确保存删除、清空和插入；旧修订根据加载基线合并互不冲突的修改，保持活跃消息及工具对象引用。
-- 归档提交顺序为临时文件写入、文件 `fsync`、原子 `rename`、推进基线，再更新快照。档案失败不得更新快照；档案已提交而快照失败仍返回成功。
-- 列表枚举快照与档案 ID 的并集。首次快照失败后，孤立档案仍须可读、可列出；缓存继续失败时使用内存有界预览。
-- Codex App 运行态写入 `_history/_turns/<id>.json`，包含完整正文、工具及映射；有界运行态文件只作预览。重启枚举完整运行态，恢复消息提交成功后才清理，异常档案保留证据。
+- 可信来源保存在存储实例的 `WeakMap`，不能凭 JSON 的修订字段伪造。基线只引用清单，不保留整份正文字符串。当前修订精确保存窗口内删除和插入，未加载前后缀原样保留；跨未知前缀的重复 ID 保留已提交原文。旧修订按单消息三方合并，保持活跃消息及工具对象引用。主动清空须明确 `markComplete(session, { reset: true })`。
+- 归档提交顺序为修改块写入、文件 `fsync`、原子 `rename`，完成协调所需的块读取，再原子提交清单、推进基线、更新有界快照。清单失败不得推进基线或更新快照；已提交而快照失败仍返回成功。每32次提交回收无引用块，跨存储实例的活跃旧基线通过弱引用保护，清理失败不改变提交结果。
+- 可信同修订保存仅读取最多256字节的修订头并复用不可变清单；修订已变化才读取当前清单。任务状态版本保护使用同一次提交的清单，不为单个字段重复加载历史或清单。普通保存保留更高任务版本，任务看板通过 `taskBoardMetadata=true` 显式提交其负责的更新或删除；受保护状态仅在提交成功后同步到活跃对象。克隆只复制JSON容器，比较使用规范JSON值的结构比较，不为正文生成序列化副本。
+- 列表枚举快照与档案 ID 的并集，排除 `_turns` 保留目录及同名旧文件。首次快照失败后，孤立档案仍须可读、可列出；缓存继续失败时使用内存有界预览。
+- Codex App 运行态写入 `_history/_turns/<id>.json`，包含完整正文、工具及映射，保留原 `version:1` 格式。读取直接构造对象，写入按小段转义正文并聚合写出，单次读写最多64KiB字节；不生成整份JSON原文或写出缓冲。运行态读取结果仍为完整对象，不能声称总内存与正文大小无关。有界运行态文件只作预览。重启枚举完整运行态，恢复消息提交成功后才清理，异常档案保留证据。
 - 用户提问必须保存成功后才启动 runtime 或接受 steer；完成、重启恢复及跨会话返回必须检查保存结果，失败保留可重试内容。CLI 恢复标识须区分回合，同一已提交回合不可因清理失败再次追加。
 - 确认原始边界后的旧前缀必须先进入自身档案。`complete=false` 保留旧缺口状态，不能因创建档案就宣称旧历史完整。
+- 首屏和重连只读取最近12条；向前分页每次读取24条，目标消息预取受最大页数限制。表单和撤回使用单消息窗口，历史查重和附件枚举按块执行；任务看板只读取和保存元数据。
 - 响应的 `historyCursor` 是尚未展示的已有消息数；正数允许分页。`historyAvailable=false` 只说明旧来源待核实，不能阻断正文或用户目录。完整档案响应 `historySource='archive'`、`historyAvailable=true`。
 
 ## 4. 校验与错误矩阵
@@ -62,6 +75,11 @@ resolveSessionHistory(session)    // { messages, source, available, recoverable
 ## 6. 必需回归与断言
 
 - `scripts/session-history-store-unit.js`：实际生产保存和读取入口、超限内容、存储重开、两类写失败、孤立档案、并发及活跃引用、删除/清空/撤回、确认前缀先归档。
+- 同一脚本还须覆盖默认尾部、中间窗口及元数据保存保留未加载历史，不同加载范围并发合并、清空防复活、失败后重试和未加载前缀 ID 去重。
+- 同一脚本还须覆盖同修订保存只读修订头、更高任务版本整体保护、任务看板显式删除以及清单失败后任务状态和可信基线不提前推进。
+- `scripts/json-persistence-unit.js`：编码与读取对照原生JSON及项目bigint/Map/Set转换，覆盖toJSON单次求值、对象键、UTF-8和代理对跨段、短读短写、非法JSON及编码中途异常的原子失败保护。
+- `scripts/runtime-state-memory-unit.js`：独立子进程在256MiB堆参数下读写80MiB旧v1完整运行态，正文与工具映射摘要逐项一致；检查单次64KiB字节读写及write/fsync/rename失败保留旧文件、无临时文件残留。合成峰值不能代表生产或任意并发量。
+- `scripts/session-history-memory-unit.js`：独立子进程在256MiB堆上限下流式迁移70.5MiB旧归档，执行尾部/元数据保存和完整分页；逐条摘要校验所有历史，监测RSS、旧文件读取块大小和块复用。合成夹具的结果不能当作生产进程测量。
 - 真实完成与恢复路径使用超限正文和工具，断言归档原样读回；不能仅绕过生产入库函数直接构造消息数组。
 - 真实 runtime 事件覆盖纯工具、纯文本与结构块混合、Claude user/tool_result；恢复覆盖图片内容块、提交失败保留以及重复恢复幂等性。任务看板的克隆适配器需重新可信加载并只更新元数据。
 - `scripts/session-history-unit.js` 与 `scripts/history-frontend-unit.js`：57 条、首屏 12 条、剩余 45 条在来源待核实状态下仍全部可读，顺序正确、无重复，用户目录完成索引。
@@ -79,7 +97,8 @@ writeFileAtomicSync(sessionPath(session.id), buildSessionJsonForPersist(session)
 session.messages.push({ content: entry.fullText });
 const committed = store.save(session);
 try {
-  const preview = buildSessionJsonForPersist({ ...committed.session, historyArchiveRevision: committed.revision });
+  const tail = store.loadTail(session.id, 180, { maxBytes: 2 * 1024 * 1024 });
+  const preview = buildSessionJsonForPersist({ ...tail, historyArchiveRevision: committed.revision });
   writeFileAtomicSync(sessionPath(session.id), preview.json);
 } catch (error) {
   // 完整档案已提交，缓存失败不改成历史保存失败。
diff --git a/.trellis/tasks/10-11-remove-compact-followup/check.jsonl b/.trellis/tasks/10-11-remove-compact-followup/check.jsonl
new file mode 100644
index 0000000..2887c74
--- /dev/null
+++ b/.trellis/tasks/10-11-remove-compact-followup/check.jsonl
@@ -0,0 +1,2 @@
+{"_example": "Fill with {\"file\": \"<path>\", \"reason\": \"<why>\"}. Put spec/research files only — no code paths. Run `python3 .trellis/scripts/get_context.py --mode packages` to list available specs. Delete this line once real entries are added."}
+{"file": ".trellis/spec/backend/index.md", "reason": "核对最小修改与文案验收"}
diff --git a/.trellis/tasks/10-11-remove-compact-followup/implement.jsonl b/.trellis/tasks/10-11-remove-compact-followup/implement.jsonl
new file mode 100644
index 0000000..d68527e
--- /dev/null
+++ b/.trellis/tasks/10-11-remove-compact-followup/implement.jsonl
@@ -0,0 +1,2 @@
+{"_example": "Fill with {\"file\": \"<path>\", \"reason\": \"<why>\"}. Put spec/research files only — no code paths. Run `python3 .trellis/scripts/get_context.py --mode packages` to list available specs. Delete this line once real entries are added."}
+{"file": ".trellis/spec/backend/index.md", "reason": "遵守后端规范，仅修改提示文案"}
diff --git a/.trellis/tasks/10-11-remove-compact-followup/prd.md b/.trellis/tasks/10-11-remove-compact-followup/prd.md
new file mode 100644
index 0000000..6aae532
--- /dev/null
+++ b/.trellis/tasks/10-11-remove-compact-followup/prd.md
@@ -0,0 +1,18 @@
+# 删除多余会话提示
+
+用户明确要求去掉“下次继续在同一会话发送即可。”这句话。
+
+## 修改范围
+
+仅修改 `server.js` 中 `compactDoneMessage` 的 Codex App、Codex、Claude Code 三个返回值，去掉该句及前面的逗号，并以句号结束原生 `/compact` 完成说明。
+
+## 完成条件
+
+- 三种引擎均不再输出该句。
+- 保留各引擎原有的压缩完成说明。
+- `node --check server.js` 通过，代码差异仅包含三处文案修改。
+- 不增加测试文件，不重启当前服务。
+
+## 规范判断
+
+此次仅调整提示文案，没有新增架构或实现约定，无需更新规范。
diff --git a/.trellis/tasks/10-11-remove-compact-followup/task.json b/.trellis/tasks/10-11-remove-compact-followup/task.json
new file mode 100644
index 0000000..f0a9a4d
--- /dev/null
+++ b/.trellis/tasks/10-11-remove-compact-followup/task.json
@@ -0,0 +1,26 @@
+{
+  "id": "remove-compact-followup",
+  "name": "remove-compact-followup",
+  "title": "删除压缩完成提示中的多余句子",
+  "description": "",
+  "status": "completed",
+  "dev_type": null,
+  "scope": null,
+  "package": null,
+  "priority": "P2",
+  "creator": "shiyue",
+  "assignee": "shiyue",
+  "createdAt": "2026-10-11",
+  "completedAt": "2026-10-11",
+  "branch": null,
+  "base_branch": "main",
+  "worktree_path": null,
+  "commit": null,
+  "pr_url": null,
+  "subtasks": [],
+  "children": [],
+  "parent": null,
+  "relatedFiles": [],
+  "notes": "已删除三种引擎压缩完成提示中的多余句子；语法检查、差异检查和独立审查通过。",
+  "meta": {}
+}
diff --git a/.trellis/tasks/10-14-history-memory-audit/check.jsonl b/.trellis/tasks/10-14-history-memory-audit/check.jsonl
new file mode 100644
index 0000000..cf677af
--- /dev/null
+++ b/.trellis/tasks/10-14-history-memory-audit/check.jsonl
@@ -0,0 +1,2 @@
+{"_example": "Fill with {\"file\": \"<path>\", \"reason\": \"<why>\"}. Put spec/research files only — no code paths. Run `python3 .trellis/scripts/get_context.py --mode packages` to list available specs. Delete this line once real entries are added."}
+{"file": ".trellis/spec/backend/session-history.md", "reason": "完整性与隔离回归"}
diff --git a/.trellis/tasks/10-14-history-memory-audit/implement.jsonl b/.trellis/tasks/10-14-history-memory-audit/implement.jsonl
new file mode 100644
index 0000000..feff3ce
--- /dev/null
+++ b/.trellis/tasks/10-14-history-memory-audit/implement.jsonl
@@ -0,0 +1,2 @@
+{"_example": "Fill with {\"file\": \"<path>\", \"reason\": \"<why>\"}. Put spec/research files only — no code paths. Run `python3 .trellis/scripts/get_context.py --mode packages` to list available specs. Delete this line once real entries are added."}
+{"file": ".trellis/spec/backend/session-history.md", "reason": "完整历史、可信修订与并发契约"}
diff --git a/.trellis/tasks/10-14-history-memory-audit/prd.md b/.trellis/tasks/10-14-history-memory-audit/prd.md
new file mode 100644
index 0000000..d796551
--- /dev/null
+++ b/.trellis/tasks/10-14-history-memory-audit/prd.md
@@ -0,0 +1,7 @@
+# 完整历史内存修复
+
+保留已保存完整历史，修复整份 JSON 解析、复制、序列化基线导致的内存峰值。
+采用分块存储和按页读取，迁移旧归档时避免全量读取；保留原子提交与可信并发合并。
+验证生产入口、旧归档迁移、清空删除、运行态恢复和大归档内存。测试目录必须隔离。
+
+具体计划与发现见 .planning/2026-10-14-history-memory-fix/。
diff --git a/.trellis/tasks/10-14-history-memory-audit/task.json b/.trellis/tasks/10-14-history-memory-audit/task.json
new file mode 100644
index 0000000..ece9bee
--- /dev/null
+++ b/.trellis/tasks/10-14-history-memory-audit/task.json
@@ -0,0 +1,36 @@
+{
+  "id": "history-memory-audit",
+  "name": "history-memory-audit",
+  "title": "修复完整历史归档内存回归",
+  "description": "保留完整历史，使用不可变消息块、原子清单提交、分页读取和流式旧格式迁移，消除默认加载与保存的整份正文复制。",
+  "status": "completed",
+  "dev_type": null,
+  "scope": null,
+  "package": null,
+  "priority": "P2",
+  "creator": "shiyue",
+  "assignee": "shiyue",
+  "createdAt": "2026-10-14",
+  "completedAt": "2026-10-14",
+  "branch": null,
+  "base_branch": "main",
+  "worktree_path": null,
+  "commit": null,
+  "pr_url": null,
+  "subtasks": [],
+  "children": [],
+  "parent": null,
+  "relatedFiles": [
+    "lib/session-history-store.js",
+    "lib/json-persistence.js",
+    "server.js",
+    "scripts/session-history-store-unit.js",
+    "scripts/session-history-memory-unit.js",
+    "scripts/history-runtime-completion-unit.js",
+    "scripts/codexapp-retry-history-unit.js",
+    "scripts/regression.js",
+    ".trellis/spec/backend/session-history.md"
+  ],
+  "notes": "修复完成：34项完整历史持久化回归及完整隔离集成回归通过。70.5MiB合成旧归档在256MiB堆上限下流式迁移，RSS峰值145.9MiB；1128条消息经67页逐条摘要校验完整，6次尾部保存复用37个原始块，旧文件单次读取最多64KiB。语法与差异检查通过。未修改生产历史，未重启服务，运行进程尚未生效。",
+  "meta": {}
+}
diff --git a/.trellis/tasks/10-14-runtime-json-memory-fix/task.json b/.trellis/tasks/10-14-runtime-json-memory-fix/task.json
new file mode 100644
index 0000000..fd9cdb3
--- /dev/null
+++ b/.trellis/tasks/10-14-runtime-json-memory-fix/task.json
@@ -0,0 +1,36 @@
+{
+  "id": "runtime-json-memory-fix",
+  "name": "runtime-json-memory-fix",
+  "title": "补齐完整运行态流式JSON持久化与单次任务状态提交",
+  "description": "参考另一实例的修复，将完整运行态改为64KiB流式读写，取消序列化克隆与等值比较，归档提交内部保护更新的任务状态；保留已完成的历史分块存储和分页读取。",
+  "status": "completed",
+  "dev_type": "backend",
+  "scope": "persistence",
+  "package": null,
+  "priority": "P2",
+  "creator": "shiyue",
+  "assignee": "shiyue",
+  "createdAt": "2026-10-14",
+  "completedAt": "2026-10-14",
+  "branch": null,
+  "base_branch": "main",
+  "worktree_path": null,
+  "commit": null,
+  "pr_url": null,
+  "subtasks": [],
+  "children": [],
+  "parent": null,
+  "relatedFiles": [
+    "lib/json-persistence.js",
+    "lib/session-history-store.js",
+    "server.js",
+    "scripts/json-persistence-unit.js",
+    "scripts/runtime-state-memory-unit.js",
+    "scripts/session-history-store-unit.js",
+    "scripts/regression.js",
+    ".trellis/spec/backend/session-history.md",
+    ".trellis/spec/backend/quality-guidelines.md"
+  ],
+  "notes": "完整隔离集成回归、JSON10项、持久化38项通过。80MiB旧v1运行态在256MiB堆参数下RSS峰值210.5MiB，单次读写64KiB，正文摘要完整、write/fsync/rename失败保留旧档。未修改生产历史，未重启服务。",
+  "meta": {}
+}
diff --git a/dist-exe/cc-web-bun-linux-x64-baseline.tar.gz b/dist-exe/cc-web-bun-linux-x64-baseline.tar.gz
index 974c1a5..104e4eb 100644
Binary files a/dist-exe/cc-web-bun-linux-x64-baseline.tar.gz and b/dist-exe/cc-web-bun-linux-x64-baseline.tar.gz differ
diff --git a/lib/json-persistence.js b/lib/json-persistence.js
new file mode 100644
index 0000000..8c4ee46
--- /dev/null
+++ b/lib/json-persistence.js
@@ -0,0 +1,305 @@
+'use strict';
+
+const { StringDecoder } = require('string_decoder');
+const { types } = require('util');
+
+const BUFFER_BYTES = 64 * 1024;
+
+// 读取时直接构造容器和正文，不先拼接整份 JSON 原文。
+function createJsonReader(fs, filename) {
+  const fd = fs.openSync(filename, 'r');
+  const buffer = Buffer.allocUnsafe(BUFFER_BYTES);
+  let index = 0;
+  let length = 0;
+  let eof = false;
+  let closed = false;
+
+  function available() {
+    if (index < length) return true;
+    if (eof) return false;
+    length = fs.readSync(fd, buffer, 0, buffer.length, null);
+    index = 0;
+    eof = length === 0;
+    return !eof;
+  }
+
+  function whitespace() {
+    while (available()) {
+      const ch = buffer[index];
+      if (ch !== 32 && ch !== 9 && ch !== 10 && ch !== 13) break;
+      index += 1;
+    }
+  }
+
+  function peek() {
+    whitespace();
+    return available() ? buffer[index] : -1;
+  }
+
+  function invalid() {
+    throw new SyntaxError('持久化 JSON 结构无效或意外结束');
+  }
+
+  function consume(expected) {
+    if (peek() !== expected.charCodeAt(0)) invalid();
+    index += 1;
+  }
+
+  function string() {
+    consume('"');
+    const parts = [];
+    let pending = [];
+    let pendingChars = 0;
+    let decoder = new StringDecoder('utf8');
+    function append(text) {
+      if (!text) return;
+      pending.push(text);
+      pendingChars += text.length;
+      if (pendingChars >= 8192) {
+        parts.push(pending.join(''));
+        pending = [];
+        pendingChars = 0;
+      }
+    }
+    while (available()) {
+      const start = index;
+      while (index < length && buffer[index] >= 32 && buffer[index] !== 34 && buffer[index] !== 92) index += 1;
+      if (index > start) append(decoder.write(buffer.subarray(start, index)));
+      if (index === length) continue;
+      const ch = buffer[index++];
+      if (ch < 32) invalid();
+      // 转义字符与引号都是 ASCII，先结束前一段 UTF-8 解码。
+      append(decoder.end());
+      if (ch === 34) { parts.push(pending.join('')); return parts.join(''); }
+      decoder = new StringDecoder('utf8');
+      if (!available()) invalid();
+      const escaped = buffer[index++];
+      const simple = { 34: '"', 92: '\\', 47: '/', 98: '\b', 102: '\f', 110: '\n', 114: '\r', 116: '\t' };
+      if (Object.prototype.hasOwnProperty.call(simple, escaped)) append(simple[escaped]);
+      else if (escaped === 117) {
+        let hex = '';
+        for (let count = 0; count < 4; count += 1) {
+          if (!available()) invalid();
+          hex += String.fromCharCode(buffer[index++]);
+        }
+        if (!/^[0-9a-fA-F]{4}$/.test(hex)) invalid();
+        append(String.fromCharCode(Number.parseInt(hex, 16)));
+      } else invalid();
+    }
+    invalid();
+  }
+
+  function object(field) {
+    consume('{');
+    if (peek() === 125) { index += 1; return; }
+    while (true) {
+      if (peek() !== 34) invalid();
+      const key = string();
+      consume(':');
+      field(key);
+      if (peek() === 125) { index += 1; return; }
+      consume(',');
+    }
+  }
+
+  function array(item) {
+    consume('[');
+    if (peek() === 93) { index += 1; return; }
+    while (true) {
+      item(value());
+      if (peek() === 93) { index += 1; return; }
+      consume(',');
+    }
+  }
+
+  function value() {
+    const first = peek();
+    if (first === 34) return string();
+    if (first === 123) {
+      const result = {};
+      object(key => Object.defineProperty(result, key, {
+        value: value(), enumerable: true, writable: true, configurable: true,
+      }));
+      return result;
+    }
+    if (first === 91) {
+      const result = [];
+      array(item => result.push(item));
+      return result;
+    }
+    const parts = [];
+    while (available()) {
+      const start = index;
+      while (index < length && ![44, 125, 93, 32, 9, 10, 13].includes(buffer[index])) index += 1;
+      if (index > start) parts.push(buffer.toString('utf8', start, index));
+      if (index < length) break;
+    }
+    const token = parts.join('');
+    if (token === 'null') return null;
+    if (token === 'true') return true;
+    if (token === 'false') return false;
+    if (!/^-?(?:0|[1-9]\d*)(?:\.\d+)?(?:[eE][+-]?\d+)?$/.test(token)) invalid();
+    return Number(token);
+  }
+
+  return {
+    value, object, array,
+    end() { if (peek() !== -1) invalid(); },
+    close() { if (!closed) { closed = true; fs.closeSync(fd); } },
+  };
+}
+
+function readJsonSync(fs, filename) {
+  const reader = createJsonReader(fs, filename);
+  try {
+    const result = reader.value();
+    reader.end();
+    return result;
+  } finally {
+    reader.close();
+  }
+}
+
+// 与历史持久化既有 replacer 保持一致；toJSON 在项目类型转换之前执行。
+function jsonValue(value, key) {
+  if (value !== null && (typeof value === 'object' || typeof value === 'function' || typeof value === 'bigint')) {
+    const toJSON = value.toJSON;
+    if (typeof toJSON === 'function') value = toJSON.call(value, key);
+  }
+  if (typeof value === 'bigint') return String(value);
+  if (value instanceof Map) value = Object.fromEntries(value);
+  else if (value instanceof Set) value = [...value];
+  if (value && typeof value === 'object') {
+    if (types.isNumberObject(value)) value = Number(value);
+    else if (types.isStringObject(value)) value = String(value);
+    else if (types.isBooleanObject(value)) value = Boolean.prototype.valueOf.call(value);
+    else if (types.isBigIntObject(value)) throw new TypeError('JSON 不支持包装的 bigint');
+  }
+  if (typeof value === 'number' && !Number.isFinite(value)) return null;
+  if (value === 0) return 0;
+  if (value === undefined || typeof value === 'function' || typeof value === 'symbol') return undefined;
+  return value;
+}
+
+function cloneJsonValue(value) {
+  const ancestors = new Set();
+  function clone(item, key) {
+    item = jsonValue(item, key);
+    if (item === null || typeof item !== 'object') return item;
+    if (ancestors.has(item)) throw new TypeError('JSON 不支持循环引用');
+    ancestors.add(item);
+    try {
+      if (Array.isArray(item)) {
+        const result = [];
+        const length = item.length;
+        for (let index = 0; index < length; index += 1) result.push(clone(item[index], String(index)) ?? null);
+        return result;
+      }
+      const result = {};
+      for (const name of Object.keys(item)) {
+        const next = clone(item[name], name);
+        if (next !== undefined) Object.defineProperty(result, name, {
+          value: next, enumerable: true, writable: true, configurable: true,
+        });
+      }
+      return result;
+    } finally {
+      ancestors.delete(item);
+    }
+  }
+  return clone(value, '');
+}
+
+function writeJsonSync(fs, fd, value) {
+  const ancestors = new Set();
+  const output = Buffer.allocUnsafe(BUFFER_BYTES);
+  let used = 0;
+  function flush() {
+    let offset = 0;
+    while (offset < used) {
+      const written = fs.writeSync(fd, output, offset, used - offset, null);
+      if (!Number.isInteger(written) || written <= 0) throw new Error('持久化 JSON 写入未取得进展');
+      offset += written;
+    }
+    used = 0;
+  }
+  function append(text) {
+    const bytes = Buffer.from(text, 'utf8');
+    for (let offset = 0; offset < bytes.length;) {
+      const count = Math.min(output.length - used, bytes.length - offset);
+      bytes.copy(output, used, offset, offset + count);
+      offset += count;
+      used += count;
+      if (used === output.length) flush();
+    }
+  }
+  function string(text) {
+    append('"');
+    for (let start = 0; start < text.length;) {
+      let end = Math.min(text.length, start + 8192);
+      // 不能在分段转义处拆开 UTF-16 代理对，否则会改变实际 JSON 字节。
+      if (end < text.length && text.charCodeAt(end - 1) >= 0xd800 && text.charCodeAt(end - 1) <= 0xdbff
+        && text.charCodeAt(end) >= 0xdc00 && text.charCodeAt(end) <= 0xdfff) end -= 1;
+      append(JSON.stringify(text.slice(start, end)).slice(1, -1));
+      start = end;
+    }
+    append('"');
+  }
+  function write(item, key, arrayItem = false, prepared = false) {
+    if (!prepared) item = jsonValue(item, key);
+    if (item === undefined) {
+      if (arrayItem) { append('null'); return true; }
+      return false;
+    }
+    if (item === null) append('null');
+    else if (typeof item === 'string') string(item);
+    else if (typeof item !== 'object') append(String(item));
+    else {
+      if (ancestors.has(item)) throw new TypeError('JSON 不支持循环引用');
+      ancestors.add(item);
+      try {
+        if (Array.isArray(item)) {
+          append('[');
+          const length = item.length;
+          for (let index = 0; index < length; index += 1) {
+            if (index) append(',');
+            write(item[index], String(index), true);
+          }
+          append(']');
+        } else {
+          append('{');
+          let first = true;
+          for (const name of Object.keys(item)) {
+            // 每个字段只求值一次，避免 getter 或 toJSON 重复执行。
+            const next = jsonValue(item[name], name);
+            if (next === undefined) continue;
+            if (!first) append(',');
+            first = false;
+            string(name);
+            append(':');
+            write(next, name, false, true);
+          }
+          append('}');
+        }
+      } finally {
+        ancestors.delete(item);
+      }
+    }
+    return true;
+  }
+  if (!write(value, '')) throw new TypeError('顶层值不可持久化为 JSON');
+  flush();
+}
+
+// 合并输入已是规范 JSON 值；直接比较结构，避免为长正文制造序列化副本。
+function jsonValueEqual(left, right) {
+  if (left === right) return true;
+  if (left === null || right === null || typeof left !== 'object' || typeof right !== 'object') return false;
+  if (Array.isArray(left) !== Array.isArray(right)) return false;
+  if (Array.isArray(left)) return left.length === right.length && left.every((item, index) => jsonValueEqual(item, right[index]));
+  const keys = Object.keys(left);
+  return keys.length === Object.keys(right).length && keys.every(key => Object.prototype.hasOwnProperty.call(right, key)
+    && jsonValueEqual(left[key], right[key]));
+}
+
+module.exports = { createJsonReader, readJsonSync, writeJsonSync, cloneJsonValue, jsonValueEqual };
diff --git a/lib/session-history-store.js b/lib/session-history-store.js
index f92737b..daa9d13 100644
--- a/lib/session-history-store.js
+++ b/lib/session-history-store.js
@@ -3,6 +3,10 @@
 const nativeFs = require('fs');
 const path = require('path');
 const crypto = require('crypto');
+const { createJsonReader, readJsonSync, writeJsonSync, cloneJsonValue, jsonValueEqual } = require('./json-persistence');
+
+// 跨存储实例保护仍在使用的旧修订；弱引用不延长会话或消息的寿命。
+const liveBaselines = new Set();
 
 const SESSION_RUNTIME_KEYS = new Set([
   'ws', 'tailer', 'codexAppStateTimer', 'codexAppStateDirty', 'codexAppStateCleaned',
@@ -16,10 +20,13 @@ function createSessionHistoryStore(options = {}) {
   // 身份只留在当前存储实例，不能通过 JSON 快照伪造可信完整加载或修订。
   const loadedStates = new WeakMap();
   const removedIds = new Set();
+  const chunkMaxBytes = options.chunkMaxBytes || 2 * 1024 * 1024;
+  const chunkMaxMessages = options.chunkMaxMessages || 64;
+  let commits = 0;
 
   function validId(value) {
     const id = String(value || '');
-    if (!/^[a-zA-Z0-9_-]+$/.test(id)) throw Object.assign(new Error('会话归档 ID 无效'), { code: 'history_invalid_id' });
+    if (!/^[a-zA-Z0-9_-]+$/.test(id) || id === '_turns') throw Object.assign(new Error('会话归档 ID 无效'), { code: 'history_invalid_id' });
     return id;
   }
 
@@ -27,18 +34,116 @@ function createSessionHistoryStore(options = {}) {
     return path.join(historyDir, `${validId(id)}.json`);
   }
 
-  function readRecord(id) {
-    let json;
+  function archiveDir(id) {
+    return path.join(historyDir, validId(id));
+  }
+
+  function manifestPath(id) {
+    return path.join(archiveDir(id), 'manifest.json');
+  }
+
+  function chunkPath(id, file) {
+    if (!/^[a-f0-9]{64}\.json$/.test(file)) throw new Error('完整会话归档块引用无效');
+    return path.join(archiveDir(id), 'chunks', file);
+  }
+
+  function stringify(value) {
+    return JSON.stringify(value, (key, item) => {
+      if (typeof item === 'bigint') return String(item);
+      if (item instanceof Map) return Object.fromEntries(item);
+      if (item instanceof Set) return [...item];
+      return item;
+    });
+  }
+
+  function sessionMetadata(session) {
+    const metadata = Object.create(null);
+    for (const key of Object.keys(session)) {
+      if (key === 'messages' || key === 'historySnapshotBaseIndex' || key === 'historySnapshotCount'
+        || key === 'historyArchiveRevision' || SESSION_RUNTIME_KEYS.has(key)) continue;
+      Object.defineProperty(metadata, key, { value: session[key], enumerable: true });
+    }
+    return cloneJsonValue(metadata);
+  }
+
+  function chunkWriter(id) {
+    const entries = [];
+    let pending = [];
+    let bytes = 2;
+    function flush() {
+      if (!pending.length) return;
+      const json = `[${pending.map(item => item.json).join(',')}]`;
+      const file = `${crypto.createHash('sha256').update(json).digest('hex')}.json`;
+      const target = chunkPath(id, file);
+      if (!fs.existsSync(target)) writeAtomicJson(target, null, json);
+      pending.forEach((item, index) => {
+        Object.assign(item.entry, { id: item.id || null, role: item.role, digest: item.digest, file, index, bytes: item.bytes });
+        entries.push(item.entry);
+      });
+      pending = [];
+      bytes = 2;
+    }
+    function add(message) {
+      const json = stringify(message);
+      if (json === undefined) throw new Error('完整会话消息不可序列化');
+      const size = Buffer.byteLength(json);
+      if (pending.length && (bytes + size + 1 > chunkMaxBytes || pending.length >= chunkMaxMessages)) flush();
+      const entry = {};
+      pending.push({ json, id: message?.id, role: message?.role || null,
+        digest: crypto.createHash('sha256').update(json).digest('hex'), bytes: size, entry });
+      bytes += size + 1;
+      // 单条超大消息仍完整保存，不能按预览限额截断。
+      if (bytes >= chunkMaxBytes || pending.length >= chunkMaxMessages) flush();
+      return entry;
+    }
+    return { add, finish() { flush(); return entries; } };
+  }
+
+  function migrateLegacy(id) {
+    if (!fs.existsSync(filePath(id))) return null;
+    const reader = createJsonReader(fs, filePath(id));
+    const record = Object.create(null);
+    const metadata = Object.create(null);
+    const writer = chunkWriter(id);
+    let hasMessages = false;
     try {
-      json = fs.readFileSync(filePath(id), 'utf8');
+      reader.object(key => {
+        if (key !== 'session') { record[key] = reader.value(); return; }
+        reader.object(field => {
+          if (field === 'messages') {
+            hasMessages = true;
+            reader.array(message => { if (message?.ccwebPersistenceNotice !== true) writer.add(message); });
+          } else Object.defineProperty(metadata, field, { value: reader.value(), enumerable: true, configurable: true });
+        });
+      });
+      reader.end();
+    } finally {
+      reader.close();
+    }
+    if (record.version !== 1 || typeof record.revision !== 'string' || !record.revision
+      || metadata.id !== id || !hasMessages || typeof record.complete !== 'boolean') {
+      throw Object.assign(new Error('完整会话归档格式无效'), { code: 'history_invalid_archive' });
+    }
+    const entries = writer.finish();
+    const manifest = { version: 2, revision: record.revision, complete: record.complete,
+      resetRevision: record.resetRevision || null, session: sessionMetadata(metadata), entries };
+    // 旧单文件保留为迁移来源；所有块成功落盘后，清单才成为唯一提交点。
+    writeAtomicJson(manifestPath(id), manifest);
+    return manifest;
+  }
+
+  function readRecord(id) {
+    let record;
+    try {
+      record = JSON.parse(fs.readFileSync(manifestPath(id), 'utf8'));
     } catch (error) {
-      if (error?.code === 'ENOENT') return null;
+      if (error?.code === 'ENOENT') return migrateLegacy(id);
       throw error;
     }
-    const record = JSON.parse(json);
-    if (record?.version !== 1 || typeof record.revision !== 'string' || !record.revision
-      || record.session?.id !== id || !Array.isArray(record.session.messages)
-      || typeof record.complete !== 'boolean') {
+    if (record?.version !== 2 || typeof record.revision !== 'string' || !record.revision
+      || record.session?.id !== id || !Array.isArray(record.entries) || typeof record.complete !== 'boolean'
+      || record.entries.some(entry => !/^[a-f0-9]{64}\.json$/.test(entry.file)
+        || !/^[a-f0-9]{64}$/.test(entry.digest) || !Number.isSafeInteger(entry.index) || entry.index < 0)) {
       throw Object.assign(new Error('完整会话归档格式无效'), { code: 'history_invalid_archive' });
     }
     return record;
@@ -47,18 +152,125 @@ function createSessionHistoryStore(options = {}) {
   function state(session) {
     const value = session && loadedStates.get(session);
     if (!value) return null;
-    const { baseline, ...metadata } = value;
-    return metadata;
+    return { id: value.id, revision: value.revision, complete: value.complete, source: value.source,
+      resetRevision: value.resetRevision || null, start: value.start || 0,
+      end: value.end, total: value.manifest?.entries.length, partial: value.partial === true };
+  }
+
+  function register(session, manifest, start, end, partial) {
+    const baseline = { id: session.id, revision: manifest.revision, complete: manifest.complete,
+      source: 'archive', resetRevision: manifest.resetRevision || null, manifest, start, end, partial, directory: archiveDir(session.id) };
+    loadedStates.set(session, baseline);
+    liveBaselines.add(new WeakRef(baseline));
+  }
+
+  function entryReader(id) {
+    const cache = new Map();
+    return entry => {
+      let messages = cache.get(entry.file);
+      if (!messages) {
+        const json = fs.readFileSync(chunkPath(id, entry.file), 'utf8');
+        if (crypto.createHash('sha256').update(json).digest('hex') !== entry.file.slice(0, -5)) {
+          throw new Error('完整会话归档块校验失败');
+        }
+        messages = JSON.parse(json);
+        if (!Array.isArray(messages)) throw new Error('完整会话归档块格式无效');
+        cache.set(entry.file, messages);
+        if (cache.size > 2) cache.delete(cache.keys().next().value);
+      }
+      const message = messages[entry.index];
+      if (message === undefined) throw new Error('完整会话归档消息引用无效');
+      return message;
+    };
+  }
+
+  function loadRange(id, record, start, end, partial) {
+    const session = cloneJsonValue(record.session);
+    const read = entryReader(id);
+    session.messages = record.entries.slice(start, end).map(read);
+    session.historySnapshotBaseIndex = start;
+    session.historySnapshotCount = session.messages.length;
+    register(session, record, start, end, partial);
+    return session;
   }
 
   function load(id) {
-    const record = readRecord(validId(id));
+    id = validId(id);
+    const record = readRecord(id);
+    return record ? loadRange(id, record, 0, record.entries.length, false) : null;
+  }
+
+  function loadTail(id, count = 180, limits = {}) {
+    id = validId(id);
+    const record = readRecord(id);
     if (!record) return null;
-    loadedStates.set(record.session, {
-      id, revision: record.revision, complete: record.complete, source: 'archive',
-      resetRevision: record.resetRevision || null, baseline: JSON.stringify(record.session),
-    });
-    return record.session;
+    const end = record.entries.length;
+    let start = Math.max(0, end - Math.max(0, Math.trunc(count)));
+    if (Number.isFinite(limits.maxBytes) && limits.maxBytes > 0) {
+      let bytes = 0;
+      for (let index = end - 1; index >= start; index -= 1) {
+        const size = record.entries[index].bytes || 0;
+        if (bytes && bytes + size > limits.maxBytes) { start = index + 1; break; }
+        bytes += size;
+      }
+    }
+    return loadRange(id, record, start, end, start > 0);
+  }
+
+  function loadMetadata(id) {
+    return loadTail(id, 0);
+  }
+
+  function loadWindow(id, start, end = start + 1) {
+    id = validId(id);
+    const record = readRecord(id);
+    if (!record) return null;
+    const total = record.entries.length;
+    start = Math.max(0, Math.min(total, Math.trunc(start)));
+    end = Math.max(start, Math.min(total, Math.trunc(end)));
+    return loadRange(id, record, start, end, start > 0 || end < total);
+  }
+
+  function forEachMessage(id, callback) {
+    id = validId(id);
+    const record = readRecord(id);
+    if (!record) return;
+    const read = entryReader(id);
+    for (let index = 0; index < record.entries.length; index += 1) callback(read(record.entries[index]), index);
+  }
+
+  function findMessage(id, predicate, before = Infinity) {
+    id = validId(id);
+    const record = readRecord(id);
+    if (!record) return null;
+    const read = entryReader(id);
+    for (let index = Math.min(record.entries.length, before) - 1; index >= 0; index -= 1) {
+      const message = read(record.entries[index]);
+      if (predicate(message, index)) return { message, index };
+    }
+    return null;
+  }
+
+  function loadHistoryPage(id, before, count = 24) {
+    id = validId(id);
+    const record = readRecord(id);
+    if (!record) return null;
+    const total = record.entries.length;
+    const end = Number.isFinite(before) ? Math.max(0, Math.min(total, Math.trunc(before))) : total;
+    const start = Math.max(0, end - Math.max(0, Math.trunc(count)));
+    const read = entryReader(id);
+    return { messages: record.entries.slice(start, end).map(read), total, start, end,
+      complete: record.complete, revision: record.revision };
+  }
+
+  function messageIndex(id, messageId) {
+    const record = readRecord(validId(id));
+    return record ? record.entries.findIndex(entry => entry.id === messageId) : -1;
+  }
+
+  function countMessages(id, role) {
+    const record = readRecord(validId(id));
+    return record ? record.entries.filter(entry => !role || entry.role === role).length : null;
   }
 
   function markLegacy(session) {
@@ -76,28 +288,16 @@ function createSessionHistoryStore(options = {}) {
     if (!previous || previous.id !== session.id) {
       throw Object.assign(new Error('只能确认可信加载会话的历史状态'), { code: 'history_untrusted_source' });
     }
-    loadedStates.set(session, { ...previous, complete: true, reset: options.reset === true });
+    const confirmed = { ...previous, complete: true, reset: options.reset === true, partial: false };
+    loadedStates.set(session, confirmed);
+    if (confirmed.manifest) liveBaselines.add(new WeakRef(confirmed));
     session.historySnapshotBaseIndex = 0;
     session.historySnapshotCount = session.messages.length;
     return () => loadedStates.set(session, previous);
   }
 
-  function serializeSession(session) {
-    // 完整档案没有文本、消息数、数组长度或深度裁剪；不可序列化时整次提交失败。
-    const json = JSON.stringify(session, function replacer(key, value) {
-      if (this === session && SESSION_RUNTIME_KEYS.has(key)) return undefined;
-      if (typeof value === 'bigint') return String(value);
-      if (value instanceof Map) return Object.fromEntries(value);
-      if (value instanceof Set) return [...value];
-      return value;
-    });
-    const persisted = JSON.parse(json);
-    if (!Array.isArray(persisted.messages)) throw new Error('完整会话消息必须为数组');
-    return persisted;
-  }
-
   function equal(left, right) {
-    return JSON.stringify(left) === JSON.stringify(right);
+    return jsonValueEqual(left, right);
   }
 
   function plainObject(value) {
@@ -187,13 +387,14 @@ function createSessionHistoryStore(options = {}) {
     return persisted;
   }
 
-  function writeAtomicJson(target, record) {
+  function writeAtomicJson(target, record, json) {
     fs.mkdirSync(path.dirname(target), { recursive: true });
     const temporary = `${target}.${process.pid}.${crypto.randomUUID()}.tmp`;
     let fd;
     try {
       fd = fs.openSync(temporary, 'wx', 0o600);
-      fs.writeFileSync(fd, JSON.stringify(record), 'utf8');
+      if (json === undefined) writeJsonSync(fs, fd, record);
+      else fs.writeFileSync(fd, json, 'utf8');
       fs.fsyncSync(fd);
       fs.closeSync(fd);
       fd = undefined;
@@ -206,10 +407,6 @@ function createSessionHistoryStore(options = {}) {
     }
   }
 
-  function writeRecord(id, record) {
-    writeAtomicJson(filePath(id), record);
-  }
-
   function turnPath(id) {
     return path.join(turnsDir, `${validId(id)}.json`);
   }
@@ -220,7 +417,7 @@ function createSessionHistoryStore(options = {}) {
 
   function loadTurn(id) {
     try {
-      const state = JSON.parse(fs.readFileSync(turnPath(id), 'utf8'));
+      const state = readJsonSync(fs, turnPath(id));
       if (state?.sessionId !== id || state.agent !== 'codexapp') throw new Error('完整运行态归档无效');
       return state;
     } catch (error) {
@@ -244,11 +441,16 @@ function createSessionHistoryStore(options = {}) {
     }
   }
 
-  function save(session) {
+  function save(session, options = {}) {
     const id = validId(session?.id);
     const previous = loadedStates.get(session);
     if (removedIds.has(id)) throw Object.assign(new Error('已删除会话不能由旧对象重新保存'), { code: 'history_removed' });
-    const current = readRecord(id);
+    if (previous?.source === 'archive' && !fs.existsSync(manifestPath(id))) {
+      throw Object.assign(new Error('完整会话归档已移除，拒绝旧对象重新创建'), { code: 'history_removed' });
+    }
+    // 同修订只核对文件头，可信清单已经是不可变基线；旧修订才重新读取当前清单。
+    const current = previous?.source === 'archive' && revision(id) === previous.revision
+      ? previous.manifest : readRecord(id);
     if (current) {
       if (previous?.source !== 'archive' || previous.id !== id) {
         throw Object.assign(new Error('受限预览不能覆盖完整会话归档'), { code: 'history_untrusted_source' });
@@ -259,47 +461,177 @@ function createSessionHistoryStore(options = {}) {
     const complete = current?.complete || (previous ? previous.complete
       : !session.messages?.some(message => message?.ccwebPersistenceNotice === true)
         && !(Number(session.historySnapshotBaseIndex) > 0));
-    let persisted = serializeSession(session);
+    if (!Array.isArray(session.messages)) throw new Error('完整会话消息必须为数组');
+    let metadata = sessionMetadata(session);
+    let taskTrackingPreserved = null;
+    const currentTracking = current?.session.taskTracking;
+    if (!options.taskBoardMetadata && currentTracking && typeof currentTracking === 'object') {
+      const persistedVersion = Number.isSafeInteger(currentTracking.version) ? currentTracking.version : 0;
+      const incomingVersion = Number.isSafeInteger(metadata.taskTracking?.version) ? metadata.taskTracking.version : -1;
+      if (incomingVersion < persistedVersion) {
+        metadata.taskTracking = cloneJsonValue(currentTracking);
+        taskTrackingPreserved = { incomingVersion, persistedVersion };
+      }
+    }
     const rebased = !!current && previous.revision !== current.revision;
-    if (rebased) {
-      const baseline = JSON.parse(previous.baseline);
-      if (!identifiedArray(baseline.messages) || !identifiedArray(persisted.messages) || !identifiedArray(current.session.messages)) {
+    const baseEntries = previous?.manifest?.entries || [];
+    const viewedEntries = previous?.partial ? baseEntries.slice(previous.start, previous.end) : baseEntries;
+    const descriptors = [];
+    const positions = new Map();
+    for (const message of session.messages) {
+      if (message?.ccwebPersistenceNotice === true) continue;
+      const json = stringify(message);
+      if (json === undefined) throw new Error('完整会话消息不可序列化');
+      const descriptor = { id: message?.id || null, digest: crypto.createHash('sha256').update(json).digest('hex'), message };
+      // 同 ID 的最新片段保留最初位置，不同气泡即使同 turn 也分别保存。
+      if (descriptor.id && positions.has(descriptor.id)) descriptors[positions.get(descriptor.id)] = descriptor;
+      else {
+        if (descriptor.id) positions.set(descriptor.id, descriptors.length);
+        descriptors.push(descriptor);
+      }
+    }
+    let ordered = descriptors;
+    let start = previous?.partial ? previous.start : 0;
+    let end;
+    const read = entryReader(id);
+    const currentEntries = current?.entries || [];
+    const resetChanged = rebased && (current.resetRevision || null) !== (previous.resetRevision || null);
+    if (rebased && !resetChanged) {
+      if ([viewedEntries, descriptors, currentEntries].some(entries => !entries.every(entry => typeof entry.id === 'string' && entry.id))) {
         throw Object.assign(new Error('旧修订缺少可靠消息 ID，拒绝覆盖新历史'), { code: 'history_stale_unidentified' });
       }
-      if (baseline.messages.length > 0 && persisted.messages.length === 0 && !equal(current.session.messages, baseline.messages)) {
+      if (!previous.partial && baseEntries.length > 0 && descriptors.length === 0
+        && !equal(currentEntries.map(entry => entry.digest), baseEntries.map(entry => entry.digest))) {
         throw Object.assign(new Error('清空前历史已经更新，请重新加载'), { code: 'history_stale_clear' });
       }
-      if ((current.resetRevision || null) !== (previous.resetRevision || null)) {
-        // 清空提交后旧运行对象只能同步元数据，旧线程的历史和输出不能复活。
-        persisted.messages = baseline.messages;
-        for (const key of ['claudeSessionId', 'codexThreadId', 'codexAppThreadId', 'historySnapshotBaseIndex', 'historySnapshotCount']) {
-          if (Object.prototype.hasOwnProperty.call(baseline, key)) persisted[key] = baseline[key];
-          else delete persisted[key];
+      const baseById = new Map(viewedEntries.map(entry => [entry.id, entry]));
+      const incomingById = new Map(descriptors.map(entry => [entry.id, entry]));
+      const currentIds = new Set(currentEntries.map(entry => entry.id));
+      ordered = [];
+      for (const entry of currentEntries) {
+        const base = baseById.get(entry.id);
+        const next = incomingById.get(entry.id);
+        if (!base) { ordered.push(entry); continue; }
+        if (!next) {
+          if (entry.digest !== base.digest) ordered.push(entry);
+          continue;
         }
+        if (next.digest === base.digest || next.digest === entry.digest) ordered.push(entry);
+        else if (entry.digest === base.digest) ordered.push(next);
+        else ordered.push({ id: next.id, incoming: next.message, base, current: entry });
       }
-      persisted = mergeValue(baseline, persisted, current.session);
+      const orderedIds = new Set(ordered.map(entry => entry.id));
+      for (let index = 0; index < descriptors.length; index += 1) {
+        const item = descriptors[index];
+        if (baseById.has(item.id) || currentIds.has(item.id) || orderedIds.has(item.id)) continue;
+        let position = -1;
+        for (let next = index + 1; next < descriptors.length; next += 1) {
+          position = ordered.findIndex(entry => entry.id === descriptors[next].id);
+          if (position >= 0) break;
+        }
+        if (position < 0) {
+          for (let anchor = index - 1; anchor >= 0; anchor -= 1) {
+            const found = ordered.findIndex(entry => entry.id === descriptors[anchor].id);
+            if (found >= 0) { position = found + 1; break; }
+          }
+        }
+        ordered.splice(position < 0 ? ordered.length : position, 0, item);
+        orderedIds.add(item.id);
+      }
+      if (previous.partial) {
+        // 只协调原加载窗口及窗口内的并发新增，不能把未加载的后缀变成内存基线。
+        const prefixIds = new Set(baseEntries.slice(0, previous.start).map(entry => entry.id));
+        const suffixIds = new Set(baseEntries.slice(previous.end).map(entry => entry.id));
+        const lastPrefix = ordered.reduce((found, entry, index) => prefixIds.has(entry.id) ? index : found, -1);
+        start = lastPrefix >= 0 ? lastPrefix + 1 : Math.min(previous.start, ordered.length);
+        const firstSuffix = ordered.findIndex(entry => suffixIds.has(entry.id));
+        end = firstSuffix >= 0 ? firstSuffix : ordered.length;
+        if (previous.start === previous.end && descriptors.length === 0) start = end;
+      }
+    } else if (resetChanged) {
+      // 清空后的旧对象只同步元数据，旧线程及输出不能复活。
+      ordered = currentEntries;
+      start = previous.partial ? currentEntries.length : 0;
+      end = currentEntries.length;
+      for (const key of ['claudeSessionId', 'codexThreadId', 'codexAppThreadId']) {
+        if (Object.prototype.hasOwnProperty.call(previous.manifest.session, key)) metadata[key] = previous.manifest.session[key];
+        else delete metadata[key];
+      }
+    } else if (previous?.partial) {
+      const prefix = currentEntries.slice(0, previous.start);
+      const suffix = currentEntries.slice(previous.end);
+      const unseenIds = new Set([...prefix, ...suffix].filter(entry => entry.id).map(entry => entry.id));
+      // 重试的稳定 ID 若已存在于未加载区间，保留已提交原文和位置。
+      ordered = [...prefix, ...descriptors.filter(entry => !entry.id || !unseenIds.has(entry.id)), ...suffix];
+      end = ordered.length - suffix.length;
     }
-    if (complete) {
-      persisted.historySnapshotBaseIndex = 0;
-      persisted.historySnapshotCount = persisted.messages.length;
+    if (rebased) metadata = mergeValue(previous.manifest.session, metadata, current.session);
+    const writer = chunkWriter(id);
+    const currentById = new Map(currentEntries.filter(entry => entry.id).map(entry => [entry.id, entry]));
+    const entries = ordered.map((item, index) => {
+      if (item.file) return item;
+      const same = item.id ? currentById.get(item.id) : currentEntries[index];
+      if (same && same.digest === item.digest) return same;
+      const message = item.current
+        ? mergeValue(read(item.base), cloneJsonValue(item.incoming), read(item.current))
+        : item.message;
+      return writer.add(message);
+    });
+    writer.finish();
+    const nextRevision = crypto.randomUUID();
+    const resetRevision = previous?.reset ? nextRevision : current?.resetRevision || null;
+    const record = { version: 2, revision: nextRevision, complete, resetRevision, session: metadata, entries };
+    end ??= entries.length;
+    let updated;
+    let synchronizedMetadata;
+    if (rebased || end - start !== session.messages.length) {
+      const byId = new Map(session.messages.filter(message => message?.id).map(message => [message.id, message]));
+      // 提交前完成所有可能失败的块读取；提交失败不修改活跃消息和可信基线。
+      updated = entries.slice(start, end).map(entry => ({ target: byId.get(entry.id), persisted: read(entry) }));
+      // 活跃元数据可以原位更新，不能与不可变清单基线共用新增的对象引用。
+      synchronizedMetadata = cloneJsonValue(metadata);
     }
-    const revision = crypto.randomUUID();
-    const resetRevision = previous?.reset ? revision : current?.resetRevision || null;
-    const record = { version: 1, revision, complete, resetRevision, session: persisted };
-    writeRecord(id, record);
-    // 只有原子提交后才推进修订，失败重试仍以原修订为基线。
-    loadedStates.set(session, { id, revision, complete, resetRevision, source: 'archive', baseline: JSON.stringify(persisted) });
-    if (rebased) {
-      // 流式处理闭包可能持有气泡和工具对象，合并时按 ID 原位协调，保持后续 delta 写入目标。
-      synchronizeValue(session, persisted, true);
+    const synchronizedTracking = taskTrackingPreserved && !updated ? cloneJsonValue(metadata.taskTracking) : null;
+    writeAtomicJson(manifestPath(id), record);
+    if (updated) {
+      session.messages.length = updated.length;
+      updated.forEach((item, index) => { session.messages[index] = synchronizeValue(item.target, item.persisted); });
+      synchronizeValue(session, { ...synchronizedMetadata, messages: session.messages }, true);
+    }
+    if (synchronizedTracking) session.taskTracking = synchronizeValue(session.taskTracking, synchronizedTracking);
+    session.historySnapshotBaseIndex = start;
+    session.historySnapshotCount = session.messages.length;
+    register(session, record, start, end, start > 0 || end < entries.length);
+    if (++commits % 32 === 0) {
+      // 只回收当前清单和活跃旧修订都不再引用的块，清理失败不改变已提交结果。
+      try { collectChunks(id, record); } catch {}
+    }
+    return { revision: nextRevision, complete, session, rebased, taskTrackingPreserved };
+  }
+
+  function collectChunks(id, current) {
+    const files = new Set(current.entries.map(entry => entry.file));
+    for (const reference of liveBaselines) {
+      const baseline = reference.deref();
+      if (!baseline) { liveBaselines.delete(reference); continue; }
+      if (baseline.id === id && baseline.directory === archiveDir(id)) baseline.manifest.entries.forEach(entry => files.add(entry.file));
+    }
+    const directory = path.join(archiveDir(id), 'chunks');
+    for (const file of fs.readdirSync(directory)) {
+      if (/^[a-f0-9]{64}\.json$/.test(file) && !files.has(file)) fs.unlinkSync(path.join(directory, file));
     }
-    return { revision, complete, session: persisted, rebased };
   }
 
   function listIds() {
     try {
-      return fs.readdirSync(historyDir).filter(name => /^[a-zA-Z0-9_-]+\.json$/.test(name))
-        .map(name => name.slice(0, -5));
+      const ids = new Set();
+      for (const name of fs.readdirSync(historyDir)) {
+        // 运行态归档属于保留目录，不参与会话归档枚举。
+        if (name === '_turns' || name === '_turns.json') continue;
+        if (/^[a-zA-Z0-9_-]+\.json$/.test(name)) ids.add(name.slice(0, -5));
+        else if (/^[a-zA-Z0-9_-]+$/.test(name) && fs.existsSync(manifestPath(name))) ids.add(name);
+      }
+      return [...ids];
     } catch (error) {
       if (error?.code === 'ENOENT') return [];
       throw error;
@@ -309,10 +641,11 @@ function createSessionHistoryStore(options = {}) {
   function revision(id) {
     let fd;
     try {
-      fd = fs.openSync(filePath(id), 'r');
+      const recordPath = fs.existsSync(manifestPath(id)) ? manifestPath(id) : filePath(id);
+      fd = fs.openSync(recordPath, 'r');
       const head = Buffer.alloc(256);
       const count = fs.readSync(fd, head, 0, head.length, 0);
-      const matched = /^\{"version":1,"revision":"([0-9a-f-]{36})",/.exec(head.toString('utf8', 0, count));
+      const matched = /^\{"version":[12],"revision":"([0-9a-f-]{36})",/.exec(head.toString('utf8', 0, count));
       if (!matched) throw new Error('完整会话归档修订无效');
       return matched[1];
     } catch (error) {
@@ -328,11 +661,13 @@ function createSessionHistoryStore(options = {}) {
     try { fs.unlinkSync(filePath(id)); } catch (error) {
       if (error?.code !== 'ENOENT') throw error;
     }
+    fs.rmSync(archiveDir(id), { recursive: true, force: true });
     removedIds.add(id);
     removeTurn(id);
   }
 
-  return { load, save, state, markLegacy, markComplete, listIds, revision, remove, saveTurn, loadTurn, removeTurn, listTurnIds, historyDir };
+  return { load, loadTail, loadMetadata, loadWindow, forEachMessage, findMessage, loadHistoryPage, messageIndex, countMessages, save, state, markLegacy, markComplete,
+    listIds, revision, remove, saveTurn, loadTurn, removeTurn, listTurnIds, historyDir };
 }
 
 module.exports = { createSessionHistoryStore };
diff --git a/scripts/codexapp-retry-history-unit.js b/scripts/codexapp-retry-history-unit.js
index 39672c1..8df2943 100644
--- a/scripts/codexapp-retry-history-unit.js
+++ b/scripts/codexapp-retry-history-unit.js
@@ -73,7 +73,7 @@ function createApi(dir, options = {}) {
     'textByteLength', 'truncateTextValue', 'sanitizePersistValue', 'sanitizeToolCallsForPersist',
     'mapToPairs', 'codexAppStatePath', 'codexAppTurnKey', 'serializeCodexAppEntry',
     'buildCodexAppStateJson', 'writeCodexAppTurnState', 'persistCodexAppTurnState',
-    'cleanupCodexAppTurnState', 'loadCodexAppTurnState', 'hasCodexAppTurnMessage',
+    'cleanupCodexAppTurnState', 'loadCodexAppTurnState', 'findSessionMessage', 'hasCodexAppTurnMessage',
     'appendCodexAppRecoveryNotice', 'recoverCodexAppTurnState',
     'hasRuntimeOutput', 'retryTailText', 'retryPreviewValue', 'buildCodexRetryToolSummary',
     'shouldUseCodexAppContinuationRetry', 'buildCodexAppContinuationRetryText',
diff --git a/scripts/history-runtime-completion-unit.js b/scripts/history-runtime-completion-unit.js
index ca74b03..9e24404 100644
--- a/scripts/history-runtime-completion-unit.js
+++ b/scripts/history-runtime-completion-unit.js
@@ -135,6 +135,7 @@ function createCliCompletionApi(dir, options = {}) {
         'hasRuntimeOutput',
         'codexOutputContent',
         'cliRunKey',
+        'findSessionMessage',
         'hasCliRunMessage',
         'isContextLimitError',
         'handleProcessComplete',
@@ -248,6 +249,7 @@ function createCodexAppStateApi(dir, options = {}) {
         'writeCodexAppTurnState',
         'loadCodexAppTurnState',
         'cleanupCodexAppTurnState',
+        'findSessionMessage',
         'hasCodexAppTurnMessage',
         'appendCodexAppRecoveryNotice',
         'recoverCodexAppTurnState',
@@ -410,6 +412,7 @@ function createCrossConversationApi(dir, options = {}) {
   const sent = [];
   const pending = new Map();
   const api = new Function('fs', 'path', 'crypto', 'dir', 'storeApi', 'pending', 'sent', 'options', 'CCWEB_REPLY_MODES', `
+    const sessionHistoryStore = storeApi.sessionHistoryStore;
     const wsSend = (ws, payload) => sent.push(payload);
     const loadSession = storeApi.loadSession;
     const saveSession = session => (options.failSave ? false : storeApi.saveSession(session));
@@ -427,6 +430,7 @@ function createCrossConversationApi(dir, options = {}) {
       'setPendingCrossConversationReply',
       'updatePendingCrossConversationReply',
       'deletePendingCrossConversationReply',
+      'findSessionMessage',
       'hasProcessedCrossConversationReply',
       'extractCrossConversationReplyText',
       'buildCrossConversationReplyContent',
@@ -536,7 +540,7 @@ function runTests() {
     assert.equal(seedApi.saveSession(sessionFixture(sessionId, 'codex', [
       { id: 'user-before-cli', role: 'user', content: '读取异常前已经保存的问题' },
     ])), true);
-    const archivePath = path.join(dir, '_history', `${sessionId}.json`);
+    const archivePath = path.join(dir, '_history', sessionId, 'manifest.json');
     const archiveBefore = fs.readFileSync(archivePath, 'utf8');
     const fullText = 'CLI 完成时必须保留的唯一输出';
     const runPath = writeRunArtifacts(dir, sessionId, {
@@ -579,7 +583,7 @@ function runTests() {
     assert.equal(seedApi.saveSession(sessionFixture(sessionId, 'codexapp', [
       { id: 'user-before-app', role: 'user', content: '读取异常前已经保存的 App 问题' },
     ])), true);
-    const archivePath = path.join(dir, '_history', `${sessionId}.json`);
+    const archivePath = path.join(dir, '_history', sessionId, 'manifest.json');
     const archiveBefore = fs.readFileSync(archivePath, 'utf8');
     // 同 CLI 夹具：损坏真实档案制造“会话暂不可读”，恢复时先修复档案再补交。
     const corruptedArchive = '{损坏的会话归档：Codex App 读取失败夹具';
diff --git a/scripts/json-persistence-unit.js b/scripts/json-persistence-unit.js
new file mode 100644
index 0000000..180cf3f
--- /dev/null
+++ b/scripts/json-persistence-unit.js
@@ -0,0 +1,262 @@
+#!/usr/bin/env node
+'use strict';
+
+const assert = require('node:assert/strict');
+const fs = require('node:fs');
+const os = require('node:os');
+const path = require('node:path');
+const { readJsonSync, writeJsonSync, cloneJsonValue, jsonValueEqual } = require('../lib/json-persistence');
+const { createSessionHistoryStore } = require('../lib/session-history-store');
+
+const BLOCK_BYTES = 64 * 1024;
+
+function nativeJson(value) {
+  return JSON.stringify(value, (key, item) => {
+    if (typeof item === 'bigint') return String(item);
+    if (item instanceof Map) return Object.fromEntries(item);
+    if (item instanceof Set) return [...item];
+    return item;
+  });
+}
+
+function temporaryRoot() {
+  if (process.platform === 'linux' && typeof fs.statfsSync === 'function') {
+    try {
+      const stat = fs.statfsSync('/dev/shm');
+      if (Number(stat.bavail) * Number(stat.bsize) >= 32 * 1024 * 1024) return '/dev/shm';
+    } catch {}
+  }
+  return os.tmpdir();
+}
+
+function runTests() {
+  const dir = fs.mkdtempSync(path.join(temporaryRoot(), 'ccweb-json-persistence-'));
+  const failures = [];
+  let checks = 0;
+  let sequence = 0;
+  function check(name, callback) {
+    try {
+      callback();
+      checks += 1;
+      console.log(`通过：${name}`);
+    } catch (error) {
+      failures.push(name);
+      console.error(`失败：${name}：${error.stack}`);
+    }
+  }
+  function rawFile(json) {
+    const filename = path.join(dir, `input-${++sequence}.json`);
+    fs.writeFileSync(filename, json);
+    return filename;
+  }
+  function encode(value, filesystem = fs) {
+    const filename = path.join(dir, `output-${++sequence}.json`);
+    const fd = fs.openSync(filename, 'wx', 0o600);
+    try { writeJsonSync(filesystem, fd, value); } finally { fs.closeSync(fd); }
+    return { filename, json: fs.readFileSync(filename, 'utf8') };
+  }
+  function assertNative(value) {
+    const expectedJson = nativeJson(value);
+    const expected = JSON.parse(expectedJson);
+    const output = encode(value);
+    assert.equal(output.json, expectedJson);
+    assert.deepEqual(readJsonSync(fs, output.filename), expected);
+    assert.deepEqual(cloneJsonValue(value), expected);
+  }
+
+  try {
+    check('JSON基本类型、数值边界与控制字符与原生持久化语义一致', () => {
+      const samples = [null, true, false, 0, -0, 1.25, 1e-100, 1e100, NaN, Infinity, -Infinity,
+        '', '中文🙂\u0000\b\f\n\r\t\\"/\u2028\u2029', '\ud800\udfff', 9007199254740993n];
+      samples.forEach(assertNative);
+      assertNative({ values: samples, boxed: [new Number(4), new String('包装文字'), new Boolean(false)] });
+    });
+
+    check('BigInt、Map、Set、日期与toJSON保持项目转换及键参数', () => {
+      function fixture() {
+        return {
+          bigint: 123456789012345678901234567890n,
+          map: new Map([['a', 1n], ['__proto__', { own: true }], ['set', new Set([2, 3])]]),
+          set: new Set(['x', 4n]),
+          date: new Date('2026-10-14T01:02:03.456Z'),
+          custom: { toJSON(key) { return { key, value: 9n }; } },
+          array: [{ toJSON(key) { return `数组键 ${key}`; } }],
+        };
+      }
+      assertNative(fixture());
+      assertNative({ toJSON(key) { return { rootKey: key, value: new Map([['ok', true]]) }; } });
+      for (const action of ['write', 'clone']) {
+        let reads = 0;
+        let calls = 0;
+        const custom = {
+          get toJSON() {
+            reads += 1;
+            return function (key) { calls += 1; assert.equal(this, custom); return { key, value: '原值' }; };
+          },
+        };
+        const result = action === 'write' ? JSON.parse(encode({ custom }).json) : cloneJsonValue({ custom });
+        assert.deepEqual(result, { custom: { key: 'custom', value: '原值' } });
+        assert.equal(reads, 1, 'toJSON属性只能读取一次');
+        assert.equal(calls, 1, 'toJSON只能执行一次');
+      }
+    });
+
+    check('对象省略与数组空洞置null、重复引用及危险属性名完整保存', () => {
+      const shared = { stable: '原值', nested: ['完整内容'] };
+      const object = JSON.parse('{"__proto__":{"value":"自己的属性"},"constructor":"构造键","prototype":"普通键"}');
+      object.missing = undefined;
+      object.callback = () => 1;
+      object.symbol = Symbol('省略');
+      object.array = [undefined, () => 1, Symbol('数组位置'), , shared, shared];
+      object.left = shared;
+      object.right = shared;
+      assertNative(object);
+      const cloned = cloneJsonValue(object);
+      assert.equal(Object.hasOwn(cloned, '__proto__'), true);
+      assert.deepEqual(cloned.__proto__, { value: '自己的属性' });
+      assert.equal(Object.hasOwn(cloned, 'missing'), false);
+      assert.equal(cloned.array.length, 6);
+      assert.deepEqual(cloned.array.slice(0, 4), [null, null, null, null]);
+    });
+
+    check('容器复制隔离原对象并保留不可变字符串值', () => {
+      const text = '必须保留完整正文🙂'.repeat(20000);
+      const source = { text, nested: { rows: [{ value: 1 }] } };
+      const cloned = cloneJsonValue(source);
+      assert.notEqual(cloned, source);
+      assert.notEqual(cloned.nested, source.nested);
+      assert.notEqual(cloned.nested.rows, source.nested.rows);
+      assert.notEqual(cloned.nested.rows[0], source.nested.rows[0]);
+      assert.equal(cloned.text, text);
+      cloned.nested.rows[0].value = 2;
+      assert.equal(source.nested.rows[0].value, 1);
+      assert.equal(jsonValueEqual(source, cloneJsonValue(source)), true);
+      assert.equal(jsonValueEqual(source, cloned), false);
+      assert.equal(jsonValueEqual(cloneJsonValue({ value: NaN, omitted: undefined }), { value: null }), true);
+      assert.equal(jsonValueEqual(cloneJsonValue([undefined, , Infinity]), [null, null, null]), true);
+      assert.equal(jsonValueEqual(cloneJsonValue(10n), '10'), true);
+      assert.equal(jsonValueEqual(cloneJsonValue(new Map([['value', 1]])), { value: 1 }), true);
+      assert.equal(jsonValueEqual({ left: 1, right: { value: 2 } }, { right: { value: 2 }, left: 1 }), true);
+      assert.equal(jsonValueEqual(undefined, undefined), true);
+      assert.equal(jsonValueEqual(undefined, null), false);
+    });
+
+    check('顶层不可持久化值拒绝提交且循环引用失败', () => {
+      for (const value of [undefined, () => 1, Symbol('顶层')]) {
+        assert.equal(cloneJsonValue(value), undefined);
+        assert.throws(() => encode(value), TypeError);
+      }
+      const cyclic = { text: '已经写出的字段' };
+      cyclic.self = cyclic;
+      assert.throws(() => encode(cyclic), TypeError);
+      assert.throws(() => cloneJsonValue(cyclic), TypeError);
+    });
+
+    check('64KiB边界跨UTF-8、JSON转义和长字符串时完整读取', () => {
+      const prefix = '{"text":"';
+      const utf8Json = prefix + 'a'.repeat(BLOCK_BYTES - Buffer.byteLength(prefix) - 1) + '🙂中文","tail":{"value":true}}';
+      const escapedJson = prefix + 'b'.repeat(BLOCK_BYTES - Buffer.byteLength(prefix) - 1) + '\\uD83D\\uDE42\\n\\"\\\\","tail":[1,2,3]}';
+      for (const json of [utf8Json, escapedJson, '\r\n ' + '[1e-3,true,null,{"duplicate":1,"duplicate":2}]' + '\t ']) {
+        const filename = rawFile(json);
+        let maxRead = 0;
+        const filesystem = new Proxy(fs, { get(target, key) {
+          if (key === 'readFileSync') return () => { throw new Error('流式读取禁止整文件readFileSync'); };
+          if (key === 'readSync') return (fd, buffer, offset, length, position) => {
+            maxRead = Math.max(maxRead, length);
+            assert(length <= BLOCK_BYTES);
+            return target.readSync(fd, buffer, offset, length, position);
+          };
+          return target[key];
+        } });
+        assert.deepEqual(readJsonSync(filesystem, filename), JSON.parse(json));
+        assert(maxRead > 0 && maxRead <= BLOCK_BYTES);
+      }
+    });
+
+    check('多次短读不丢UTF-8字节和转义，读取错误关闭文件', () => {
+      const json = '{"text":"中文🙂\\n\\uD83D\\uDE42\\\\\\\"","number":-2.5e+3,"rows":[true,null,{"own":1}]}';
+      const filename = rawFile(json);
+      let opened = 0;
+      let closed = 0;
+      let failRead = false;
+      const filesystem = new Proxy(fs, { get(target, key) {
+        if (key === 'openSync') return (...args) => { opened += 1; return target.openSync(...args); };
+        if (key === 'closeSync') return (...args) => { closed += 1; return target.closeSync(...args); };
+        if (key === 'readSync') return (fd, buffer, offset, length, position) => {
+          if (failRead) throw new Error('模拟读取中断');
+          return target.readSync(fd, buffer, offset, Math.min(length, 3), position);
+        };
+        return target[key];
+      } });
+      assert.deepEqual(readJsonSync(filesystem, filename), JSON.parse(json));
+      failRead = true;
+      assert.throws(() => readJsonSync(filesystem, filename), /模拟读取中断/);
+      assert.equal(closed, opened, '读取成功或失败均应关闭文件');
+    });
+
+    check('非法JSON、截断值、尾随内容与控制字符均拒绝', () => {
+      const invalid = ['', ' ', '{', '[1,', '{"a":}', '{"a":1,}', '[1,]', 'true false', 'nullx', '+1', '01', '1.', '1e',
+        'NaN', 'Infinity', 'undefined', '\ufeff{}', '{unquoted:1}', '"未闭合', '"\\x01"', '"\\u12"', '"\n"', '"\u0000"'];
+      for (const json of invalid) {
+        assert.throws(() => JSON.parse(json));
+        assert.throws(() => readJsonSync(fs, rawFile(json)), `非法JSON必须拒绝：${JSON.stringify(json)}`);
+      }
+      for (const json of ['1e400', '-0', '[1,2,3]', '{"__proto__":{"own":true},"constructor":4}']) {
+        assert.deepEqual(readJsonSync(fs, rawFile(json)), JSON.parse(json));
+      }
+    });
+
+    check('分段编码每次最多64KiB且正确处理短写', () => {
+      const value = { text: '中文🙂\\"\n\u0000'.repeat(25000), nested: { lines: ['保持原值'] } };
+      let maxWrite = 0;
+      let calls = 0;
+      const filesystem = new Proxy(fs, { get(target, key) {
+        if (key === 'writeFileSync') return () => { throw new Error('流式编码禁止整文件writeFileSync'); };
+        if (key === 'writeSync') return (fd, data, ...args) => {
+          calls += 1;
+          const bytes = typeof data === 'string' ? Buffer.byteLength(data, typeof args[1] === 'string' ? args[1] : 'utf8') : args[1] ?? data.length;
+          maxWrite = Math.max(maxWrite, bytes);
+          assert(bytes <= BLOCK_BYTES, `单次编码写入 ${bytes} 字节超出64KiB`);
+          // 固定短写发生在字节缓冲层，不能以UTF-16字符数量当作已写字节数。
+          if (typeof data === 'string') {
+            const encoded = Buffer.from(data, typeof args[1] === 'string' ? args[1] : 'utf8');
+            return target.writeSync(fd, encoded, 0, Math.min(11, encoded.length), args[0] ?? null);
+          }
+          return target.writeSync(fd, data, args[0] ?? 0, Math.min(11, bytes), args[2] ?? null);
+        };
+        return target[key];
+      } });
+      const output = encode(value, filesystem);
+      assert.equal(output.json, nativeJson(value));
+      assert(calls > 1);
+      assert(maxWrite <= BLOCK_BYTES);
+    });
+
+    check('JSON中途编码异常保留原子归档且无临时文件残留', () => {
+      const store = createSessionHistoryStore({ sessionsDir: dir });
+      const id = 'json-atomic-failure';
+      const original = { version: 1, agent: 'codexapp', sessionId: id, fullText: '上次完整运行态', toolCalls: [] };
+      store.saveTurn(id, original);
+      const filename = path.join(dir, '_history', '_turns', `${id}.json`);
+      const oldBytes = fs.readFileSync(filename);
+      const cyclic = { ...original, fullText: '新正文'.repeat(100000) };
+      cyclic.self = cyclic;
+      assert.throws(() => store.saveTurn(id, cyclic), TypeError);
+      const customFailure = { ...original, fullText: '已编码新正文'.repeat(100000), tail: { toJSON() { throw new Error('模拟toJSON异常'); } } };
+      assert.throws(() => store.saveTurn(id, customFailure), /模拟toJSON异常/);
+      assert.deepEqual(fs.readFileSync(filename), oldBytes);
+      assert.deepEqual(store.loadTurn(id), original);
+      assert.equal(fs.readdirSync(path.dirname(filename)).some(name => name.endsWith('.tmp')), false);
+    });
+  } finally {
+    fs.rmSync(dir, { recursive: true, force: true });
+  }
+  if (failures.length) {
+    console.error(`JSON持久化回归失败：${failures.length} 项，已通过 ${checks} 项`);
+    process.exitCode = 1;
+  } else console.log(`JSON持久化回归通过：${checks} 项`);
+  return { checks, failures };
+}
+
+if (require.main === module) runTests();
+module.exports = { runTests };
diff --git a/scripts/regression.js b/scripts/regression.js
index 5cc1dfe..3aa0e80 100644
--- a/scripts/regression.js
+++ b/scripts/regression.js
@@ -4748,7 +4748,7 @@ function assertServerSessionHistoryRequestIdContract() {
 }
 
 function assertHistoryRecallContract() {
-  for (const script of ['session-history-store-unit.js', 'session-history-unit.js', 'history-runtime-unit.js', 'history-runtime-completion-unit.js', 'codex-rollouts-unit.js', 'history-frontend-unit.js', 'codexapp-retry-history-unit.js', 'streaming-retry-frontend-unit.js', 'assistant-bubble-controls-unit.js']) {
+  for (const script of ['json-persistence-unit.js', 'runtime-state-memory-unit.js', 'session-history-store-unit.js', 'session-history-memory-unit.js', 'session-history-unit.js', 'history-runtime-unit.js', 'history-runtime-completion-unit.js', 'codex-rollouts-unit.js', 'history-frontend-unit.js', 'codexapp-retry-history-unit.js', 'streaming-retry-frontend-unit.js', 'assistant-bubble-controls-unit.js']) {
     const result = spawnSync(process.execPath, [path.join(REPO_DIR, 'scripts', script)], { encoding: 'utf8', timeout: 60000 });
     assert(result.status === 0, `${script}: ${result.stderr || result.stdout || result.error}`);
   }
@@ -4828,7 +4828,8 @@ function assertHistoryRecallContract() {
     'Paged history requests should use the resolved full history and echo requestId'
   );
   assert(
-    /prefetchChunks: targetMessageIndex === null \? 0/.test(serverSource),
+    /const prefetchChunks = targetMessageIndex === null \? 0/.test(serverSource)
+      && /Math\.min\(HISTORY_MAX_CHUNKS_PER_LOAD,/.test(serverSource),
     'Normal session loads should keep older history on demand instead of prefetching it all'
   );
 
diff --git a/scripts/runtime-state-memory-unit.js b/scripts/runtime-state-memory-unit.js
new file mode 100644
index 0000000..88a3210
--- /dev/null
+++ b/scripts/runtime-state-memory-unit.js
@@ -0,0 +1,238 @@
+#!/usr/bin/env node
+'use strict';
+
+const assert = require('node:assert/strict');
+const fs = require('node:fs');
+const os = require('node:os');
+const path = require('node:path');
+const crypto = require('node:crypto');
+const { spawnSync } = require('node:child_process');
+const { createSessionHistoryStore } = require('../lib/session-history-store');
+
+const ID = 'synthetic-runtime-memory';
+const TARGET_BYTES = 80 * 1024 * 1024;
+const BLOCK_BYTES = 64 * 1024;
+const LARGE_PIECE = 'a'.repeat(32 * 1024 - 16) + '\\引号"\n';
+const ASCII_PIECE = 'b'.repeat(32 * 1024 - 16) + '\\quote"\n';
+const SPECIAL = JSON.parse('{"text":"中文🙂\\n\\\\\\\"","__proto__":{"own":"保留值"},"constructor":"普通属性"}');
+const startedAt = Date.now();
+
+function stage(message) {
+  process.stderr.write(`[运行态内存回归 +${((Date.now() - startedAt) / 1000).toFixed(2)} 秒] ${message}\n`);
+}
+
+function temporaryRoot() {
+  // 此项测编码和解析的内存峰值；慢盘fsync会耗尽60秒预算，优先真实tmpfs。
+  if (process.platform === 'linux' && typeof fs.statfsSync === 'function') {
+    try {
+      const stat = fs.statfsSync('/dev/shm');
+      fs.accessSync('/dev/shm', fs.constants.W_OK);
+      if (Number(stat.bavail) * Number(stat.bsize) >= 512 * 1024 * 1024) return '/dev/shm';
+    } catch {}
+  }
+  return os.tmpdir();
+}
+
+function textHash(value) {
+  const hash = crypto.createHash('sha256');
+  for (let offset = 0; offset < value.length; offset += 32 * 1024) hash.update(value.slice(offset, offset + 32 * 1024));
+  return hash.digest('hex');
+}
+
+// 资料由父进程直接写标准version:1 JSON，不通过待测编码器制造测试基线。
+function writeFixture(sessionsDir) {
+  const directory = path.join(sessionsDir, '_history', '_turns');
+  fs.mkdirSync(directory, { recursive: true });
+  const filename = path.join(directory, `${ID}.json`);
+  const header = JSON.stringify({ version: 1, agent: 'codexapp', sessionId: ID, turnId: 'synthetic-turn', turnStatus: 'running', special: SPECIAL }).slice(0, -1) + ',"fullText":"';
+  const betweenTool = '","toolCalls":[{"id":"synthetic-tool","name":"run","input":{"text":"完整输入"},"result":"';
+  const betweenDelta = '"}],"toolOutputDeltas":[["synthetic-tool","';
+  const betweenItem = '"]],"agentMessageItems":[["synthetic-item","';
+  const ending = '"]],"agentMessagePendingPrefixes":[],"lastUsage":{"inputTokens":1,"outputTokens":2}}';
+  const fixedBytes = Buffer.byteLength(header + betweenTool + betweenDelta + betweenItem + ending);
+  const toolBytes = 12 * 1024 * 1024;
+  const deltaBytes = 4 * 1024 * 1024;
+  const itemBytes = 4 * 1024 * 1024;
+  const fullTextBytes = TARGET_BYTES - fixedBytes - toolBytes - deltaBytes - itemBytes;
+  const fd = fs.openSync(filename, 'wx', 0o600);
+  function writeField(encodedBytes, piece) {
+    const encoded = JSON.stringify(piece).slice(1, -1);
+    const size = Buffer.byteLength(encoded);
+    const hash = crypto.createHash('sha256');
+    let length = 0;
+    let remaining = encodedBytes;
+    while (remaining >= size) {
+      fs.writeSync(fd, encoded);
+      hash.update(piece);
+      length += piece.length;
+      remaining -= size;
+    }
+    if (remaining) {
+      const final = 'z'.repeat(remaining);
+      fs.writeSync(fd, final);
+      hash.update(final);
+      length += final.length;
+    }
+    return { length, hash: hash.digest('hex') };
+  }
+  const expected = {};
+  try {
+    fs.writeSync(fd, header);
+    expected.fullText = writeField(fullTextBytes, ASCII_PIECE);
+    fs.writeSync(fd, betweenTool);
+    expected.result = writeField(toolBytes, LARGE_PIECE);
+    fs.writeSync(fd, betweenDelta);
+    expected.delta = writeField(deltaBytes, LARGE_PIECE);
+    fs.writeSync(fd, betweenItem);
+    expected.item = writeField(itemBytes, LARGE_PIECE);
+    fs.writeSync(fd, ending);
+  } finally { fs.closeSync(fd); }
+  assert.equal(fs.statSync(filename).size, TARGET_BYTES);
+  return { filename, expected };
+}
+
+function fileHash(filename) {
+  const hash = crypto.createHash('sha256');
+  const buffer = Buffer.allocUnsafe(BLOCK_BYTES);
+  const fd = fs.openSync(filename, 'r');
+  try {
+    let bytes;
+    while ((bytes = fs.readSync(fd, buffer, 0, buffer.length, null))) hash.update(buffer.subarray(0, bytes));
+  } finally { fs.closeSync(fd); }
+  return hash.digest('hex');
+}
+
+function trackedFilesystem(filename) {
+  const opened = new Map();
+  const metrics = { reads: 0, writes: 0, maxRead: 0, maxWrite: 0, readBytes: 0, writeBytes: 0 };
+  let failure = null;
+  let bytesSinceFailureMode = 0;
+  function runtimeFile(value) {
+    const resolved = typeof value === 'number' ? opened.get(value) || '' : path.resolve(String(value));
+    return resolved === filename || resolved.startsWith(`${filename}.`);
+  }
+  const filesystem = new Proxy(fs, { get(target, key) {
+    if (key === 'openSync') return (file, ...args) => {
+      const fd = target.openSync(file, ...args);
+      opened.set(fd, path.resolve(String(file)));
+      return fd;
+    };
+    if (key === 'closeSync') return fd => { const result = target.closeSync(fd); opened.delete(fd); return result; };
+    if (key === 'readFileSync') return (file, ...args) => {
+      assert.equal(runtimeFile(file), false, '完整运行态禁止整份readFileSync');
+      return target.readFileSync(file, ...args);
+    };
+    if (key === 'writeFileSync') return (file, ...args) => {
+      assert.equal(runtimeFile(file), false, '完整运行态禁止整份writeFileSync');
+      return target.writeFileSync(file, ...args);
+    };
+    if (key === 'readSync') return (fd, buffer, offset, length, position) => {
+      if (runtimeFile(fd)) {
+        assert(length <= BLOCK_BYTES, '单次运行态读取不能超过64KiB');
+        metrics.maxRead = Math.max(metrics.maxRead, length);
+        metrics.reads += 1;
+      }
+      const bytes = target.readSync(fd, buffer, offset, length, position);
+      if (runtimeFile(fd)) metrics.readBytes += bytes;
+      return bytes;
+    };
+    if (key === 'writeSync') return (fd, data, ...args) => {
+      if (runtimeFile(fd)) {
+        const bytes = typeof data === 'string' ? Buffer.byteLength(data, typeof args[1] === 'string' ? args[1] : 'utf8') : args[1] ?? data.length;
+        assert(bytes <= BLOCK_BYTES, '单次运行态编码写入不能超过64KiB');
+        metrics.maxWrite = Math.max(metrics.maxWrite, bytes);
+        metrics.writes += 1;
+        if (failure === 'write' && bytesSinceFailureMode >= 1024 * 1024) throw new Error('模拟运行态中途write失败');
+        const written = target.writeSync(fd, data, ...args);
+        metrics.writeBytes += written;
+        bytesSinceFailureMode += written;
+        return written;
+      }
+      return target.writeSync(fd, data, ...args);
+    };
+    if (key === 'fsyncSync') return fd => {
+      if (failure === 'fsync' && runtimeFile(fd)) throw new Error('模拟运行态fsync失败');
+      return target.fsyncSync(fd);
+    };
+    if (key === 'renameSync') return (from, to) => {
+      if (failure === 'rename' && String(to) === filename) throw new Error('模拟运行态rename失败');
+      return target.renameSync(from, to);
+    };
+    return target[key];
+  } });
+  return { fs: filesystem, metrics, fail(mode) { failure = mode; bytesSinceFailureMode = 0; } };
+}
+
+function assertComplete(state, fixture) {
+  assert.equal(state.version, 1, '旧version:1运行态须兼容');
+  assert.equal(state.agent, 'codexapp');
+  assert.equal(state.sessionId, ID);
+  assert.equal(state.turnStatus, 'running');
+  assert.deepEqual(state.special, SPECIAL);
+  for (const [name, value] of [['fullText', state.fullText], ['result', state.toolCalls[0].result], ['delta', state.toolOutputDeltas[0][1]], ['item', state.agentMessageItems[0][1]]]) {
+    assert.equal(value.length, fixture.expected[name].length, `${name} 长度发生变化`);
+    assert.equal(textHash(value), fixture.expected[name].hash, `${name} 正文摘要发生变化`);
+  }
+  assert.deepEqual(state.toolCalls[0].input, { text: '完整输入' });
+  assert.deepEqual(state.lastUsage, { inputTokens: 1, outputTokens: 2 });
+}
+
+function runChild(sessionsDir, fixture) {
+  const tracked = trackedFilesystem(fixture.filename);
+  let store = createSessionHistoryStore({ sessionsDir, fs: tracked.fs });
+  stage('开始读取旧version:1完整运行态');
+  let state = store.loadTurn(ID);
+  assertComplete(state, fixture);
+  stage('旧运行态摘要校验通过，开始分段保存');
+  store.saveTurn(ID, state);
+  const committedHash = fileHash(fixture.filename);
+  assert.equal(fs.statSync(fixture.filename).size, TARGET_BYTES, '完整持久化不能裁剪运行态');
+  stage('分段保存完成，开始原子失败注入');
+  state.turnStatus = 'new-uncommitted-status';
+  for (const mode of ['write', 'fsync', 'rename']) {
+    tracked.fail(mode);
+    assert.throws(() => store.saveTurn(ID, state), /模拟运行态/);
+    assert.equal(fileHash(fixture.filename), committedHash, `${mode}失败必须保留上次完整文件`);
+    assert.equal(fs.readdirSync(path.dirname(fixture.filename)).some(name => name.endsWith('.tmp')), false, `${mode}失败不能遗留临时文件`);
+    stage(`${mode}失败保护通过`);
+  }
+  tracked.fail(null);
+  state = null;
+  store = null;
+  if (typeof global.gc === 'function') global.gc();
+  const reopened = createSessionHistoryStore({ sessionsDir, fs: tracked.fs });
+  state = reopened.loadTurn(ID);
+  assertComplete(state, fixture);
+  assert.equal(reopened.loadTurn('missing-runtime'), null);
+  assert(tracked.metrics.reads > 1 && tracked.metrics.writes > 1);
+  console.log(JSON.stringify({ archiveMiB: TARGET_BYTES / 1024 / 1024, peakRssMiB: process.resourceUsage().maxRSS / 1024,
+    maxReadKiB: tracked.metrics.maxRead / 1024, maxWriteKiB: tracked.metrics.maxWrite / 1024,
+    reads: tracked.metrics.reads, writes: tracked.metrics.writes, failureModes: 3 }));
+}
+
+function runTests() {
+  const sessionsDir = fs.mkdtempSync(path.join(temporaryRoot(), 'ccweb-runtime-memory-'));
+  try {
+    stage(`开始生成80MiB合成完整运行态（${path.dirname(sessionsDir)}）`);
+    const fixture = writeFixture(sessionsDir);
+    stage('合成旧运行态完成');
+    const child = spawnSync(process.execPath, ['--expose-gc', '--max-old-space-size=256', __filename, '--child', sessionsDir, JSON.stringify(fixture)], {
+      encoding: 'utf8', timeout: 60000, maxBuffer: 512 * 1024,
+      stdio: ['ignore', 'pipe', process.env.CCWEB_RUNTIME_TEST_PROGRESS === '1' ? 'inherit' : 'pipe'],
+    });
+    if (child.error || child.status !== 0) process.stderr.write(child.stderr || '');
+    assert.ifError(child.error);
+    assert.equal(child.status, 0, `256MiB堆运行态子进程失败（信号：${child.signal || '无'}）：${child.stderr || child.stdout}`);
+    const result = JSON.parse(child.stdout.trim());
+    console.log(`通过：${result.archiveMiB.toFixed(1)} MiB完整运行态兼容读取、分段保存、重开后四项正文摘要一致`);
+    console.log(`通过：write/fsync/rename三类失败保留旧文件且无临时文件，单次读取/写入最大 ${result.maxReadKiB.toFixed(1)}/${result.maxWriteKiB.toFixed(1)} KiB`);
+    console.log(`内存：256 MiB堆限制下RSS峰值 ${result.peakRssMiB.toFixed(1)} MiB；读取仍持有完整运行态对象，分段处理限制临时编码副本`);
+    return result;
+  } finally { fs.rmSync(sessionsDir, { recursive: true, force: true }); }
+}
+
+if (require.main === module) {
+  if (process.argv[2] === '--child') runChild(process.argv[3], JSON.parse(process.argv[4]));
+  else runTests();
+}
+module.exports = { runTests };
diff --git a/scripts/session-history-memory-unit.js b/scripts/session-history-memory-unit.js
new file mode 100644
index 0000000..7ceb3a0
--- /dev/null
+++ b/scripts/session-history-memory-unit.js
@@ -0,0 +1,314 @@
+#!/usr/bin/env node
+'use strict';
+
+const assert = require('node:assert/strict');
+const fs = require('node:fs');
+const os = require('node:os');
+const path = require('node:path');
+const crypto = require('node:crypto');
+const { spawnSync } = require('node:child_process');
+const { createSessionHistoryStore } = require('../lib/session-history-store');
+
+const ID = 'synthetic-memory-history';
+const TARGET_BYTES = Math.round(70.5 * 1024 * 1024);
+const TAIL_COUNT = 12;
+const PAGE_COUNT = 17;
+const SAVE_COUNT = 6;
+const ORIGINAL_CONTENT = '完整历史：中文、引号"、反斜线\\、换行\n、表情🙂\n' + 'x'.repeat(62 * 1024);
+const ORIGINAL_RESULT = '完整工具输出：' + 't'.repeat(2 * 1024);
+const startedAt = Date.now();
+
+function stage(message) {
+  process.stderr.write(`[历史内存回归 +${((Date.now() - startedAt) / 1000).toFixed(2)} 秒] ${message}\n`);
+}
+
+function temporaryRoot() {
+  // 内存回归优先使用真实 tmpfs；慢盘逐块 fsync 可能耗尽 60 秒测试预算。
+  // 文件写入、校验和 fsync 都保持真实调用，原子失败语义由存储单测覆盖。
+  if (process.platform === 'linux' && typeof fs.statfsSync === 'function') {
+    try {
+      const stat = fs.statfsSync('/dev/shm');
+      fs.accessSync('/dev/shm', fs.constants.W_OK);
+      if (Number(stat.bavail) * Number(stat.bsize) >= 512 * 1024 * 1024) return '/dev/shm';
+    } catch {}
+  }
+  return os.tmpdir();
+}
+
+function originalMessage(index) {
+  return {
+    id: `original-${index}`,
+    role: index % 2 ? 'assistant' : 'user',
+    content: `${index}:${ORIGINAL_CONTENT}`,
+    timestamp: new Date(1800000000000 + index * 1000).toISOString(),
+    toolCalls: [{
+      id: `tool-${index}`,
+      name: 'synthetic-tool',
+      input: { text: '输入完整保存', nested: { array: [index, { value: '\\"\n🙂' }] } },
+      result: ORIGINAL_RESULT,
+    }],
+  };
+}
+
+function addedMessage(index) {
+  return { id: `added-${index}`, role: 'assistant', content: `新增消息 ${index}：` + 'a'.repeat(4096) };
+}
+
+function digest(value) {
+  return crypto.createHash('sha256').update(JSON.stringify(value)).digest('hex');
+}
+
+// 测试资料由父进程逐条写入，避免测试自身先建立整份大对象。
+function writeLegacyFixture(sessionsDir) {
+  const historyDir = path.join(sessionsDir, '_history');
+  fs.mkdirSync(historyDir, { recursive: true });
+  const archivePath = path.join(historyDir, `${ID}.json`);
+  const revision = crypto.randomUUID();
+  const metadata = JSON.parse('{"__proto__":{"saved":"原值"},"constructor":"保留键","deep":{"a":{"b":{"c":{"value":"完整值"}}}}}');
+  const session = { id: ID, agent: 'codexapp', codexAppThreadId: 'synthetic-thread', title: '内存回归合成资料', metadata };
+  const head = JSON.stringify({ version: 1, revision, complete: true, resetRevision: null, session }).slice(0, -2) + ',"messages":[';
+  const fd = fs.openSync(archivePath, 'wx', 0o600);
+  let bytes = Buffer.byteLength(head);
+  let count = 0;
+  const paddingHead = '],"padding":"';
+  const ending = '"}}';
+  const paddingOverhead = Buffer.byteLength(paddingHead + ending);
+  let padding;
+  let batch = [];
+  let batchBytes = 0;
+  function flushBatch() {
+    if (!batch.length) return;
+    fs.writeSync(fd, batch.join(''));
+    batch = [];
+    batchBytes = 0;
+  }
+  try {
+    fs.writeSync(fd, head);
+    while (true) {
+      const json = `${count ? ',' : ''}${JSON.stringify(originalMessage(count))}`;
+      if (bytes + Buffer.byteLength(json) + paddingOverhead > TARGET_BYTES) break;
+      batch.push(json);
+      batchBytes += Buffer.byteLength(json);
+      if (batchBytes >= 1024 * 1024) flushBatch();
+      bytes += Buffer.byteLength(json);
+      count += 1;
+    }
+    padding = 'p'.repeat(TARGET_BYTES - bytes - paddingOverhead);
+    flushBatch();
+    fs.writeSync(fd, paddingHead + padding + ending);
+  } finally {
+    fs.closeSync(fd);
+  }
+  return { archivePath, count, bytes: fs.statSync(archivePath).size, metadataHash: digest(metadata), paddingHash: digest(padding) };
+}
+
+function createTrackedFilesystem(archivePath) {
+  const opened = new Map();
+  let metrics;
+  function reset(label) {
+    metrics = { label, chunkFiles: new Set(), chunkBytes: 0, legacyBytes: 0, legacyMaxRead: 0,
+      chunkWrites: 0, chunkFsyncMs: 0, chunkFsyncs: 0, nextLegacyProgress: 8 * 1024 * 1024 };
+  }
+  reset('初始化');
+  function resolveFile(value) {
+    if (typeof value === 'number') return opened.get(value) || '';
+    return value ? path.resolve(String(value)) : '';
+  }
+  function recordRead(file, bytes) {
+    if (file === archivePath) {
+      metrics.legacyBytes += bytes;
+      metrics.legacyMaxRead = Math.max(metrics.legacyMaxRead, bytes);
+      if (metrics.legacyBytes >= metrics.nextLegacyProgress) {
+        stage(`已扫描旧归档 ${(metrics.legacyBytes / 1024 / 1024).toFixed(1)} MiB，写块 ${metrics.chunkWrites} 次，块 fsync 累计 ${(metrics.chunkFsyncMs / 1000).toFixed(2)} 秒`);
+        metrics.nextLegacyProgress += 8 * 1024 * 1024;
+      }
+    }
+    if (file.includes(`${path.sep}chunks${path.sep}`)) {
+      metrics.chunkFiles.add(file);
+      metrics.chunkBytes += bytes;
+    }
+  }
+  const filesystem = new Proxy(fs, {
+    get(target, key) {
+      if (key === 'openSync') return (file, ...args) => {
+        const fd = target.openSync(file, ...args);
+        const resolved = resolveFile(file);
+        opened.set(fd, resolved);
+        if (resolved.includes(`${path.sep}chunks${path.sep}`) && String(args[0]).includes('w')) metrics.chunkWrites += 1;
+        return fd;
+      };
+      if (key === 'closeSync') return fd => {
+        const result = target.closeSync(fd);
+        opened.delete(fd);
+        return result;
+      };
+      if (key === 'readFileSync') return (file, ...args) => {
+        const resolved = resolveFile(file);
+        assert.notEqual(resolved, archivePath, '旧完整归档必须流式读取，禁止整文件 readFileSync');
+        const value = target.readFileSync(file, ...args);
+        recordRead(resolved, typeof value === 'string' ? Buffer.byteLength(value) : value.length);
+        return value;
+      };
+      if (key === 'readSync') return (fd, ...args) => {
+        const file = resolveFile(fd);
+        const requested = typeof args[1] === 'object' ? args[1].length ?? args[0].length : args[2] ?? args[0].length;
+        if (file === archivePath) assert(requested <= 256 * 1024, '迁移旧归档的单次读取必须有界');
+        const bytes = target.readSync(fd, ...args);
+        recordRead(file, bytes);
+        return bytes;
+      };
+      if (key === 'fsyncSync') return fd => {
+        const chunk = resolveFile(fd).includes(`${path.sep}chunks${path.sep}`);
+        const started = Date.now();
+        const result = target.fsyncSync(fd);
+        if (chunk) {
+          metrics.chunkFsyncs += 1;
+          metrics.chunkFsyncMs += Date.now() - started;
+          if (metrics.chunkFsyncs % 16 === 0) stage(`块 fsync ${metrics.chunkFsyncs} 次，累计 ${(metrics.chunkFsyncMs / 1000).toFixed(2)} 秒`);
+        }
+        return result;
+      };
+      return target[key];
+    },
+  });
+  return { fs: filesystem, reset, snapshot: () => ({ ...metrics, chunkFiles: metrics.chunkFiles.size }) };
+}
+
+function runChild(sessionsDir, fixture) {
+  const tracked = createTrackedFilesystem(fixture.archivePath);
+  const store = createSessionHistoryStore({ sessionsDir, fs: tracked.fs });
+  for (const name of ['loadTail', 'loadMetadata', 'loadHistoryPage']) {
+    assert.equal(typeof store[name], 'function', `分块归档缺少 ${name} 接口`);
+  }
+  const observations = [];
+  stage('开始迁移旧归档并加载首个尾页');
+  let tail = store.loadTail(ID, TAIL_COUNT);
+  stage('旧归档迁移完成');
+  assert(tail, '旧归档迁移后必须可加载尾部');
+  assert.equal(tail.messages.length, TAIL_COUNT);
+  assert.equal(tail.messages[0].id, `original-${fixture.count - TAIL_COUNT}`);
+  assert.equal(digest(tail.messages.at(-1)), digest(originalMessage(fixture.count - 1)));
+  observations.push(tracked.snapshot());
+  const manifestPath = path.join(sessionsDir, '_history', ID, 'manifest.json');
+  const chunkDir = path.join(sessionsDir, '_history', ID, 'chunks');
+  assert(fs.existsSync(manifestPath), '旧归档应发布版本 2 清单');
+  assert.equal(JSON.parse(fs.readFileSync(manifestPath, 'utf8')).version, 2);
+  const initialChunkFiles = fs.readdirSync(chunkDir).filter(name => name.endsWith('.json'));
+  assert(initialChunkFiles.length > 2, '大归档应拆成多个独立消息块');
+
+  function assertBoundedRead(label, callback, metadataOnly = false) {
+    tracked.reset(label);
+    const result = callback();
+    const observation = tracked.snapshot();
+    assert.equal(observation.legacyBytes, 0, `${label} 不应重新扫描旧完整归档`);
+    assert(observation.chunkFiles < initialChunkFiles.length, `${label} 不应加载全部消息块`);
+    assert(observation.chunkWrites < initialChunkFiles.length, `${label} 不应重写全部消息块`);
+    if (metadataOnly) assert.equal(observation.chunkFiles, 0, `${label} 不应读取消息块`);
+    observations.push(observation);
+    return result;
+  }
+
+  const metadata = assertBoundedRead('只加载元数据', () => store.loadMetadata(ID), true);
+  assert.equal(metadata.id, ID);
+  assert.equal(digest(metadata.metadata), fixture.metadataHash);
+  assert.equal(digest(metadata.padding), fixture.paddingHash);
+  assert(!metadata.messages || metadata.messages.length === 0, '元数据接口不应携带消息正文');
+
+  for (let index = 0; index < SAVE_COUNT; index += 1) {
+    stage(`开始第 ${index + 1} 次尾部加载和保存`);
+    tail = assertBoundedRead(`第 ${index + 1} 次加载尾部`, () => store.loadTail(ID, TAIL_COUNT));
+    const lastOriginal = tail.messages.find(message => message.id === `original-${fixture.count - 1}`);
+    assert(lastOriginal, '尾页应该覆盖待更新的最后一条原始消息');
+    lastOriginal.content = originalMessage(fixture.count - 1).content + `|第 ${index + 1} 次完整修改`;
+    lastOriginal.toolCalls[0].result = ORIGINAL_RESULT + `|第 ${index + 1} 次工具输出`;
+    tail.messages.push(addedMessage(index));
+    tail.title = `已提交 ${index + 1} 次尾部更新`;
+    assertBoundedRead(`第 ${index + 1} 次保存尾部`, () => store.save(tail));
+    stage(`第 ${index + 1} 次尾部保存完成`);
+  }
+
+  const finalMetadata = assertBoundedRead('重新加载最新元数据', () => store.loadMetadata(ID), true);
+  assert.equal(finalMetadata.title, `已提交 ${SAVE_COUNT} 次尾部更新`);
+  assert.equal(digest(finalMetadata.metadata), fixture.metadataHash);
+  assert.equal(digest(finalMetadata.padding), fixture.paddingHash);
+  const reopened = createSessionHistoryStore({ sessionsDir, fs: tracked.fs });
+  let before = fixture.count + SAVE_COUNT;
+  let checked = 0;
+  let pageCount = 0;
+  let revision;
+  stage('开始重开存储并逐页校验全部历史');
+  while (before > 0) {
+    const page = assertBoundedRead(`分页 ${pageCount + 1}`, () => reopened.loadHistoryPage(ID, before, PAGE_COUNT));
+    assert.equal(page.total, fixture.count + SAVE_COUNT, '尾页保存必须保留未加载的全部历史');
+    assert.equal(page.end, before);
+    assert.equal(page.start, Math.max(0, before - PAGE_COUNT));
+    assert.equal(page.messages.length, page.end - page.start);
+    assert.equal(page.complete, true);
+    if (revision) assert.equal(page.revision, revision, '分页期间应保持同一归档修订');
+    revision = page.revision;
+    page.messages.forEach((message, offset) => {
+      const position = page.start + offset;
+      const expected = position < fixture.count ? originalMessage(position) : addedMessage(position - fixture.count);
+      if (position === fixture.count - 1) {
+        expected.content += `|第 ${SAVE_COUNT} 次完整修改`;
+        expected.toolCalls[0].result += `|第 ${SAVE_COUNT} 次工具输出`;
+      }
+      assert.equal(message.id, expected.id, `第 ${position} 条消息的顺序或稳定 ID 错误`);
+      assert.equal(digest(message), digest(expected), `第 ${position} 条正文、工具或元数据出现截断或变化`);
+      checked += 1;
+    });
+    before = page.start;
+    pageCount += 1;
+    if (pageCount % 16 === 0) stage(`已校验 ${pageCount} 页、${checked} 条消息`);
+  }
+  assert.equal(checked, fixture.count + SAVE_COUNT);
+  const currentManifest = JSON.parse(fs.readFileSync(manifestPath, 'utf8'));
+  const currentChunkFiles = new Set(currentManifest.entries.map(entry => entry.file));
+  const reusedChunks = initialChunkFiles.filter(name => currentChunkFiles.has(name)).length;
+  assert(reusedChunks > 0, '尾部更新必须复用未变化的消息块');
+  stage(`全部 ${pageCount} 页、${checked} 条历史校验完成`);
+  console.log(JSON.stringify({
+    archiveMiB: fixture.bytes / 1024 / 1024,
+    originalMessages: fixture.count,
+    checkedMessages: checked,
+    pages: pageCount,
+    saves: SAVE_COUNT,
+    peakRssMiB: process.resourceUsage().maxRSS / 1024,
+    initialChunks: initialChunkFiles.length,
+    reusedChunks,
+    maxChunksPerBoundedOperation: Math.max(...observations.slice(1).map(item => item.chunkFiles)),
+    legacyMaxReadKiB: observations[0].legacyMaxRead / 1024,
+    migrationFsyncSeconds: observations[0].chunkFsyncMs / 1000,
+  }));
+}
+
+function runTests() {
+  const sessionsDir = fs.mkdtempSync(path.join(temporaryRoot(), 'ccweb-history-memory-'));
+  try {
+    stage(`开始流式写入 70.5 MiB 合成夹具（${path.dirname(sessionsDir)}）`);
+    const fixture = writeLegacyFixture(sessionsDir);
+    stage(`夹具写入完成，共 ${fixture.count} 条原始消息`);
+    assert.equal(fixture.bytes, TARGET_BYTES);
+    const child = spawnSync(process.execPath, ['--max-old-space-size=256', __filename, '--child', sessionsDir, JSON.stringify(fixture)], {
+      encoding: 'utf8', timeout: 60000, maxBuffer: 512 * 1024,
+      stdio: ['ignore', 'pipe', process.env.CCWEB_HISTORY_TEST_PROGRESS === '1' ? 'inherit' : 'pipe'],
+    });
+    if (child.error || child.status !== 0) process.stderr.write(child.stderr || '');
+    assert.ifError(child.error);
+    assert.equal(child.status, 0, `256 MiB 堆子进程失败（信号：${child.signal || '无'}）：\n${child.stderr || child.stdout}`);
+    const result = JSON.parse(child.stdout.trim());
+    console.log(`通过：${result.archiveMiB.toFixed(1)} MiB 旧归档流式迁移，256 MiB 堆内逐页校验 ${result.checkedMessages} 条完整历史`);
+    console.log(`通过：${result.saves} 次尾部保存、${result.pages} 页读取，单次最多触达 ${result.maxChunksPerBoundedOperation}/${result.initialChunks} 个原始块`);
+    console.log(`内存：子进程 RSS 峰值 ${result.peakRssMiB.toFixed(1)} MiB；旧归档单次读取最大 ${result.legacyMaxReadKiB.toFixed(1)} KiB；复用 ${result.reusedChunks} 个原始块`);
+    return result;
+  } finally {
+    fs.rmSync(sessionsDir, { recursive: true, force: true });
+  }
+}
+
+if (require.main === module) {
+  if (process.argv[2] === '--child') runChild(process.argv[3], JSON.parse(process.argv[4]));
+  else runTests();
+}
+
+module.exports = { runTests };
diff --git a/scripts/session-history-store-unit.js b/scripts/session-history-store-unit.js
index b9438e0..c656cf1 100644
--- a/scripts/session-history-store-unit.js
+++ b/scripts/session-history-store-unit.js
@@ -36,11 +36,13 @@ function createServerHarness(sessionsDir, options = {}) {
     'sanitizeToolCallsForPersist', 'sanitizeMessageForPersist', 'sanitizeMessagesForPersist',
     'sanitizeSessionForPersist', 'buildSessionJsonForPersist', 'writeFileAtomicSync',
     'safeReadSessionJson', 'loadSession', 'preserveNewerTaskTrackingForSessionSave',
+    'findSessionMessage',
     'saveSession', 'sessionHistoryCacheKey', 'cacheSessionHistory', 'loadNativeSessionHistory',
     'resolveSessionHistory',
     'listSessionFiles', 'refreshSessionSnapshotCache', 'prepareNativeHistoryImport',
     'handleSlashCommand', 'handleDeleteSession', 'findCcwebPromptMessage', 'removeCcwebPromptMessage',
     'rollbackPersistedCodexAppSteerMessage', 'handleLoadHistoryPage',
+    'buildSessionInfoPayload', 'handleResumeSession',
   ];
   const api = new Function('fs', 'path', 'crypto', 'SESSIONS_DIR', 'sessionHistoryStore', 'rollouts', 'options', 'logs', `
     const SESSION_MAX_JSON_BYTES = options.snapshotMaxBytes || 512 * 1024;
@@ -60,6 +62,8 @@ function createServerHarness(sessionsDir, options = {}) {
     const retainedCodexAppTurns = new Map();
     const activeCodexAppGoalCommands = new Map();
     const activeCodexAppCompactions = new Map();
+    const pendingCodexCapacityRetries = new Map();
+    const wsSessionMap = new Map();
     const codexAppGoalStates = new Map();
     const pendingSlashCommands = new Map();
     const pendingCompactRetries = new Map();
@@ -83,6 +87,10 @@ function createServerHarness(sessionsDir, options = {}) {
     function wsSend(ws, payload) { responses.push(payload); }
     function attachClientRequestId(payload, source) { return { ...payload, requestId: source?.requestId }; }
     function taskTrackingSnapshotForSession() { return null; }
+    function crossConversationWaitState() { return {}; }
+    function detachWsFromActiveRuntimes() {}
+    function isSessionRunning() { return false; }
+    function attachActiveRuntimeToWs() {}
     function publicTitleMetadata() { return {}; }
     function sessionModelLabel(session) { return session.model; }
     function isCodexAppSession(session) { return session.agent === 'codexapp'; }
@@ -105,9 +113,16 @@ function createServerHarness(sessionsDir, options = {}) {
     ${pureSource}
     ${names.map(name => extract(name)).join('\n')}
     return {
-      loadSession, saveSession, resolveSessionHistory, listSessionFiles, refreshSessionSnapshotCache,
+      loadSession: (id, loadOptions = {}) => {
+        const explicitWindow = ['metadata', 'count', 'window', 'messageId', 'promptId'].some(key => Object.prototype.hasOwnProperty.call(loadOptions, key));
+        const full = Object.prototype.hasOwnProperty.call(loadOptions, 'full')
+          ? loadOptions.full : options.fullHistory !== false && !explicitWindow;
+        return loadSession(id, { ...loadOptions, full });
+      },
+      saveSession, resolveSessionHistory, listSessionFiles, refreshSessionSnapshotCache, findSessionMessage,
       prepareNativeHistoryImport, handleSlashCommand, handleDeleteSession, removeCcwebPromptMessage,
       rollbackPersistedCodexAppSteerMessage, handleLoadHistoryPage, responses, logs, sessionHistoryStore,
+      buildSessionInfoPayload, handleResumeSession,
     };
   `)(filesystem, path, crypto, sessionsDir, sessionHistoryStore, rollouts, options, logs);
   return api;
@@ -302,6 +317,16 @@ check('首次快照失败的孤立档案重开后仍可读取并参与列表且
   assert(fs.existsSync(path.join(dir, 'orphan.json')));
 });
 
+check('运行态保留目录和同名旧文件不会干扰完整归档与会话列表', dir => {
+  const api = createServerHarness(dir);
+  assert.equal(api.saveSession(fixture('listed-session', 3)), true);
+  api.sessionHistoryStore.saveTurn('listed-session', { sessionId: 'listed-session', agent: 'codexapp' });
+  fs.writeFileSync(path.join(dir, '_history', '_turns.json'), '{}');
+  assert.deepEqual(api.sessionHistoryStore.listTurnIds(), ['listed-session']);
+  assert.deepEqual(api.sessionHistoryStore.listIds(), ['listed-session']);
+  assert.deepEqual(api.listSessionFiles(), ['listed-session.json']);
+});
+
 check('可信旧修订并发追加和插入保留锚点顺序以及特殊 JSON 键', dir => {
   const api = createServerHarness(dir);
   const original = fixture('concurrent', 4);
@@ -389,7 +414,7 @@ check('档案异常禁止回退预览覆盖，删除档案后旧加载对象不
   assert.equal(api.saveSession(fixture('corrupt', 220)), true);
   const stale = api.loadSession('corrupt');
   const oldSnapshot = fs.readFileSync(path.join(dir, 'corrupt.json'), 'utf8');
-  fs.writeFileSync(path.join(dir, '_history', 'corrupt.json'), '{损坏文件');
+  fs.writeFileSync(path.join(dir, '_history', 'corrupt', 'manifest.json'), '{损坏文件');
   assert.equal(api.loadSession('corrupt'), null);
   assert.equal(api.saveSession(stale), false);
   assert.equal(fs.readFileSync(path.join(dir, 'corrupt.json'), 'utf8'), oldSnapshot);
@@ -445,7 +470,7 @@ check('旧快照的真实 rollout 前缀确认后先归档，移除 rollout 后
   const api = createServerHarness(dir, { nativeDir, nativeFiles: [rolloutPath] });
   const resolved = api.resolveSessionHistory(api.loadSession(id));
   assert.equal(resolved.messages.length, 8);
-  assert(fs.existsSync(path.join(dir, '_history', `${id}.json`)), '确认前缀后应提交自身档案');
+  assert(fs.existsSync(path.join(dir, '_history', id, 'manifest.json')), '确认前缀后应提交自身档案');
   fs.unlinkSync(rolloutPath);
   const reopened = createServerHarness(dir);
   const reloaded = reopened.loadSession(id);
@@ -462,7 +487,8 @@ check('原生日志不匹配和不存在时只返回已有旧快照并保留缺
   assert.equal(history.messages.length, 57);
   assert.equal(history.available, false);
   assert.equal(api.saveSession(loaded), true);
-  assert.equal(createServerHarness(dir).resolveSessionHistory(createServerHarness(dir).loadSession('unconfirmed')).available, false);
+  const reopened = createServerHarness(dir);
+  assert.equal(reopened.resolveSessionHistory(reopened.loadSession('unconfirmed')).available, false);
 });
 
 check('归档提交失败的旧前缀恢复只提供原快照而不宣称恢复成功', dir => {
@@ -538,6 +564,402 @@ check('生产分页出口读取57条旧快照：首屏12以外45条完整有序
   assert.equal(new Set(chunks.map(message => message.id)).size, 45);
 });
 
+check('真实默认加载650条历史只持有180条尾部且显式窗口不走完整加载', dir => {
+  const api = createServerHarness(dir, { fullHistory: false });
+  const original = fixture('bounded-default', 650);
+  assert.equal(api.saveSession(original), true);
+  const loaded = api.loadSession(original.id);
+  assert.equal(loaded.messages.length, 180);
+  assert.equal(loaded.historySnapshotBaseIndex, 470);
+  assert.deepEqual(loaded.messages, original.messages.slice(470));
+  const state = api.sessionHistoryStore.state(loaded);
+  assert.equal(state.partial, true);
+  assert.equal(state.start, 470);
+  assert.equal(state.total, 650);
+  assert.deepEqual(api.loadSession(original.id, { full: true }).messages, original.messages);
+  const fullDefault = createServerHarness(dir);
+  assert.equal(fullDefault.loadSession(original.id, { count: 7 }).messages.length, 7);
+  assert.equal(fullDefault.loadSession(original.id, { metadata: true }).messages.length, 0);
+  assert.equal(fullDefault.loadSession(original.id, { window: { start: 470, end: 650 } }).messages.length, 180);
+});
+
+check('有界尾部修改删除前插追加精确保存且未加载前缀原样保留', dir => {
+  const api = createServerHarness(dir, { fullHistory: false });
+  const original = fixture('bounded-edit', 650);
+  assert.equal(api.saveSession(original), true);
+  const loaded = api.loadSession(original.id);
+  loaded.messages[0].content = '尾部同 ID 更新';
+  loaded.messages[0].toolCalls = [{ id: 'changed-tool', input: { retained: true }, result: '完整工具结果' }];
+  loaded.messages.splice(1, 1);
+  loaded.messages.splice(2, 0, { id: 'inserted-before-tail', role: 'assistant', content: '已有气泡前插入' });
+  loaded.messages.push({ id: 'new-tail', role: 'user', content: '追加完整内容' });
+  const expected = [...original.messages.slice(0, 470), ...loaded.messages];
+  assert.equal(api.saveSession(loaded), true);
+  const restored = api.loadSession(original.id, { full: true });
+  assert.deepEqual(restored.messages, expected);
+  assert.deepEqual(restored.messages.slice(0, 470), original.messages.slice(0, 470));
+  assert.equal(restored.messages.some(message => message.id === 'message-471'), false);
+});
+
+check('中间加载窗口修改删除前插保存同时保留未加载前缀和后缀', dir => {
+  const api = createServerHarness(dir, { fullHistory: false });
+  const original = fixture('middle-window', 650);
+  original.messages[12].ccwebPrompt = { id: 'early-prompt' };
+  assert.equal(api.saveSession(original), true);
+  const tail = api.loadSession(original.id);
+  assert.deepEqual(api.findSessionMessage(tail, message => message?.ccwebPrompt?.id === 'early-prompt'), original.messages[12]);
+  const promptWindow = api.loadSession(original.id, { promptId: 'early-prompt' });
+  assert.equal(promptWindow.messages.length, 1);
+  assert.equal(promptWindow.messages[0].id, 'message-12');
+  const messageWindow = api.loadSession(original.id, { messageId: 'message-10' });
+  assert.equal(messageWindow.messages.length, 1);
+  assert.equal(messageWindow.messages[0].id, 'message-10');
+  const loaded = api.loadSession(original.id, { window: { start: 250, end: 255 } });
+  assert.equal(loaded.messages.length, 5);
+  assert.equal(loaded.historySnapshotBaseIndex, 250);
+  loaded.messages[0].content = '中间窗口同 ID 更新';
+  loaded.messages.splice(1, 1);
+  loaded.messages.splice(2, 0, { id: 'middle-insert', role: 'assistant', content: '中间窗口前插内容' });
+  const expected = [...original.messages.slice(0, 250), ...loaded.messages, ...original.messages.slice(255)];
+  assert.equal(api.saveSession(loaded), true);
+  const restored = api.loadSession(original.id, { full: true });
+  assert.deepEqual(restored.messages, expected);
+  assert.deepEqual(restored.messages.slice(0, 250), original.messages.slice(0, 250));
+  assert.deepEqual(restored.messages.slice(255), original.messages.slice(255));
+  assert.equal(restored.messages.some(message => message.id === 'message-251'), false);
+});
+
+check('仅元数据加载更新标题及taskTracking不读取或覆盖未加载消息', dir => {
+  const api = createServerHarness(dir);
+  const original = fixture('metadata-only', 650);
+  original.taskTracking = { version: 2, tasks: [{ id: 'task-a', title: '原任务', status: 'pending' }] };
+  assert.equal(api.saveSession(original), true);
+  const metadata = api.loadSession(original.id, { metadata: true });
+  assert.equal(metadata.messages.length, 0);
+  assert.equal(api.sessionHistoryStore.state(metadata).partial, true);
+  metadata.title = '仅元数据更新的标题';
+  metadata.taskTracking = { version: 3, tasks: [{ id: 'task-a', title: '新任务', status: 'completed' }] };
+  assert.equal(api.saveSession(metadata), true);
+  const restored = api.loadSession(original.id);
+  assert.equal(restored.title, metadata.title);
+  assert.deepEqual(restored.taskTracking, metadata.taskTracking);
+  assert.deepEqual(restored.messages, original.messages);
+});
+
+check('同修订任务版本保护只读取修订头且提交后同步活跃对象', dir => {
+  let tracking = false;
+  let wholeReads = 0;
+  const filesystem = new Proxy(fs, {
+    get(target, key) {
+      if (key === 'readFileSync') return (...args) => {
+        if (tracking) wholeReads += 1;
+        return target.readFileSync(...args);
+      };
+      return target[key];
+    },
+  });
+  const api = createServerHarness(dir, { fs: filesystem, fullHistory: false });
+  const original = fixture('same-task-version', 650);
+  original.taskTracking = { version: 5, statusId: 'waiting', summary: '已提交任务' };
+  assert.equal(api.saveSession(original), true);
+  const loaded = api.loadSession(original.id);
+  const taskReference = loaded.taskTracking;
+  loaded.taskTracking.version = 1;
+  loaded.taskTracking.statusId = '旧任务';
+  tracking = true;
+  const committed = api.sessionHistoryStore.save(loaded);
+  tracking = false;
+  assert.equal(wholeReads, 0, '同修订提交不得重新读取清单或消息正文');
+  assert.deepEqual(committed.taskTrackingPreserved, { incomingVersion: 1, persistedVersion: 5 });
+  assert.equal(loaded.taskTracking, taskReference, '任务对象仍原位协调');
+  assert.deepEqual(loaded.taskTracking, original.taskTracking);
+  loaded.taskTracking.summary = '提交后修改';
+  const disk = api.loadSession(original.id, { metadata: true });
+  assert.equal(disk.taskTracking.summary, '已提交任务', '活跃对象不能污染可信清单');
+  assert.equal(api.loadSession(original.id, { full: true }).messages.length, 650);
+});
+
+check('旧修订普通保存完整保留更高任务版本与流式消息引用', dir => {
+  const api = createServerHarness(dir, { fullHistory: false });
+  const original = fixture('stale-task-version', 650);
+  original.taskTracking = { version: 2, statusId: 'initial', nested: { value: '原任务' } };
+  assert.equal(api.saveSession(original), true);
+  const streaming = api.loadSession(original.id);
+  const message = streaming.messages.at(-1);
+  const metadata = api.loadSession(original.id, { metadata: true });
+  metadata.taskTracking = { version: 6, statusId: 'newer', nested: { value: '新任务' } };
+  assert.equal(api.saveSession(metadata, { taskBoardMetadata: true }), true);
+  streaming.taskTracking = { version: 4, statusId: 'stale', nested: { value: '旧对象修改' } };
+  message.content += '|增量';
+  assert.equal(api.saveSession(streaming), true);
+  assert.deepEqual(streaming.taskTracking, metadata.taskTracking);
+  assert.equal(streaming.messages.at(-1), message);
+  const restored = api.loadSession(original.id, { full: true });
+  assert.equal(restored.messages.length, 650);
+  assert.equal(restored.messages.at(-1).content, message.content);
+  assert.deepEqual(restored.taskTracking, metadata.taskTracking);
+});
+
+check('任务看板显式提交可删除任务状态而普通保存保留已提交版本', dir => {
+  const api = createServerHarness(dir);
+  const original = fixture('task-metadata-removal', 3);
+  original.taskTracking = { version: 3, statusId: 'waiting' };
+  assert.equal(api.saveSession(original), true);
+  const ordinary = api.loadSession(original.id);
+  delete ordinary.taskTracking;
+  assert.equal(api.saveSession(ordinary), true);
+  assert.deepEqual(ordinary.taskTracking, original.taskTracking);
+  const board = api.loadSession(original.id, { metadata: true });
+  delete board.taskTracking;
+  assert.equal(api.saveSession(board, { taskBoardMetadata: true }), true);
+  const restored = api.loadSession(original.id);
+  assert.equal(Object.prototype.hasOwnProperty.call(restored, 'taskTracking'), false);
+  assert.deepEqual(restored.messages, original.messages);
+});
+
+check('任务状态保护遇清单提交失败不提前修改对象或推进基线', dir => {
+  let failManifest = false;
+  const filesystem = new Proxy(fs, {
+    get(target, key) {
+      if (key === 'renameSync') return (from, to) => {
+        if (failManifest && path.basename(to) === 'manifest.json') throw new Error('模拟任务清单提交失败');
+        return target.renameSync(from, to);
+      };
+      return target[key];
+    },
+  });
+  const api = createServerHarness(dir, { fs: filesystem });
+  const original = fixture('task-failed-commit', 4);
+  original.taskTracking = { version: 5, statusId: 'saved' };
+  assert.equal(api.saveSession(original), true);
+  const loaded = api.loadSession(original.id);
+  loaded.taskTracking = { version: 1, statusId: 'stale' };
+  const pendingTracking = loaded.taskTracking;
+  const revision = api.sessionHistoryStore.state(loaded).revision;
+  failManifest = true;
+  assert.equal(api.saveSession(loaded), false);
+  assert.equal(loaded.taskTracking, pendingTracking);
+  assert.equal(loaded.taskTracking.version, 1);
+  assert.equal(api.sessionHistoryStore.state(loaded).revision, revision);
+  failManifest = false;
+  assert.equal(api.saveSession(loaded), true);
+  assert.deepEqual(loaded.taskTracking, original.taskTracking);
+});
+
+check('不同尾部加载范围的旧修订合并修改删除及新增并保留各自顺序', dir => {
+  const api = createServerHarness(dir, { fullHistory: false });
+  const original = fixture('partial-ranges', 650);
+  assert.equal(api.saveSession(original), true);
+  const narrow = api.sessionHistoryStore.loadTail(original.id, 5);
+  const wide = api.sessionHistoryStore.loadTail(original.id, 30);
+  wide.messages[0].content = '较宽窗口的修改';
+  wide.messages.splice(wide.messages.findIndex(message => message.id === 'message-640'), 1);
+  wide.messages.push({ id: 'wide-new', role: 'user', content: '较宽窗口追加' });
+  assert.equal(api.saveSession(wide), true);
+  narrow.messages[0].content = '旧修订较窄窗口的修改';
+  narrow.messages.splice(1, 0, { id: 'narrow-insert', role: 'assistant', content: '较窄窗口前插' });
+  narrow.messages.push({ id: 'narrow-new', role: 'assistant', content: '较窄窗口追加' });
+  assert.equal(api.saveSession(narrow), true);
+  const restored = api.loadSession(original.id, { full: true });
+  const expected = original.messages.filter(message => message.id !== 'message-640').map(message => ({ ...message }));
+  expected.find(message => message.id === 'message-620').content = '较宽窗口的修改';
+  expected.find(message => message.id === 'message-645').content = '旧修订较窄窗口的修改';
+  expected.splice(expected.findIndex(message => message.id === 'message-646'), 0, { id: 'narrow-insert', role: 'assistant', content: '较窄窗口前插' });
+  expected.push({ id: 'narrow-new', role: 'assistant', content: '较窄窗口追加' }, { id: 'wide-new', role: 'user', content: '较宽窗口追加' });
+  assert.deepEqual(restored.messages, expected);
+  assert.deepEqual(narrow.messages, expected.slice(644));
+});
+
+check('部分加载明确reset清空全部历史后旧运行对象只保存元数据', dir => {
+  const api = createServerHarness(dir, { fullHistory: false });
+  const original = fixture('partial-clear', 650);
+  assert.equal(api.saveSession(original), true);
+  const stale = api.loadSession(original.id);
+  const current = api.loadSession(original.id);
+  current.messages = [];
+  current.codexAppThreadId = null;
+  api.sessionHistoryStore.markComplete(current, { reset: true });
+  assert.equal(api.saveSession(current), true);
+  assert.deepEqual(api.loadSession(original.id, { full: true }).messages, []);
+  stale.messages[0].content = '清空后旧轮才返回的输出';
+  stale.messages.push({ id: 'stale-output', role: 'assistant', content: '不能复活旧历史' });
+  stale.model = '旧对象本次修改的模型';
+  assert.equal(api.saveSession(stale), true);
+  const restored = api.loadSession(original.id, { full: true });
+  assert.deepEqual(restored.messages, []);
+  assert.equal(restored.codexAppThreadId, null);
+  assert.equal(restored.model, stale.model);
+});
+
+check('尾部manifest提交失败不推进基线且重试保留并发元数据与完整前缀', dir => {
+  let failManifest = false;
+  const filesystem = new Proxy(fs, { get(target, key) {
+    if (key === 'renameSync') return (from, to) => {
+      if (failManifest && path.basename(to) === 'manifest.json') throw new Error('模拟清单提交失败');
+      return target.renameSync(from, to);
+    };
+    return target[key];
+  } });
+  const api = createServerHarness(dir, { fullHistory: false, fs: filesystem });
+  const original = fixture('partial-retry', 650);
+  assert.equal(api.saveSession(original), true);
+  const pending = api.loadSession(original.id);
+  const baselineRevision = api.sessionHistoryStore.state(pending).revision;
+  const oldSnapshot = fs.readFileSync(path.join(dir, `${original.id}.json`), 'utf8');
+  pending.messages[0].content = '失败重试后应保存的正文';
+  pending.messages.push({ id: 'retry-new', role: 'assistant', content: '只提交一次的新消息' });
+  failManifest = true;
+  assert.equal(api.saveSession(pending), false);
+  assert.equal(api.sessionHistoryStore.state(pending).revision, baselineRevision);
+  assert.equal(fs.readFileSync(path.join(dir, `${original.id}.json`), 'utf8'), oldSnapshot);
+  assert.deepEqual(api.loadSession(original.id, { full: true }).messages, original.messages);
+  failManifest = false;
+  const metadata = api.loadSession(original.id, { metadata: true });
+  metadata.title = '失败后其他对象提交的标题';
+  assert.equal(api.saveSession(metadata), true);
+  assert.equal(api.saveSession(pending), true);
+  assert.notEqual(api.sessionHistoryStore.state(pending).revision, baselineRevision);
+  const restored = api.loadSession(original.id, { full: true });
+  assert.equal(restored.title, metadata.title);
+  assert.deepEqual(restored.messages.slice(0, 470), original.messages.slice(0, 470));
+  assert.equal(restored.messages[470].content, '失败重试后应保存的正文');
+  assert.equal(restored.messages.length, 651);
+  assert.equal(restored.messages.filter(message => message.id === 'retry-new').length, 1);
+});
+
+check('不完整归档分页总量和消息不计入持久化裁剪提示', dir => {
+  const api = createServerHarness(dir, { fullHistory: false });
+  const original = fixture('incomplete-pages', 57);
+  original.messages.unshift({ id: 'persistence-notice', role: 'system', ccwebPersistenceNotice: true, content: '仅显示的旧截断提示' });
+  original.historySnapshotBaseIndex = 500;
+  const expectedMessages = original.messages.slice(1);
+  assert.equal(api.saveSession(original), true);
+  const directPage = api.sessionHistoryStore.loadHistoryPage(original.id, 57, 24);
+  assert.equal(directPage.total, 57);
+  assert.equal(directPage.complete, false);
+  const chunks = [];
+  let cursor = 57;
+  while (cursor > 0) {
+    api.handleLoadHistoryPage(null, { sessionId: original.id, before: cursor, requestId: `archive-page-${cursor}` });
+    const page = api.responses.at(-1);
+    assert.equal(page.type, 'session_history_chunk');
+    assert.equal(page.historyTotal, 57);
+    assert.equal(page.historyAvailable, false);
+    assert.equal(page.messages.some(message => message.ccwebPersistenceNotice === true), false);
+    chunks.unshift(...page.messages);
+    assert(page.historyCursor < cursor, '分页游标必须前进');
+    cursor = page.historyCursor;
+  }
+  assert.deepEqual(chunks, expectedMessages);
+});
+
+check('尾部追加ID撞未加载前缀时保留原始前缀并去重', dir => {
+  const api = createServerHarness(dir, { fullHistory: false });
+  const original = fixture('partial-collision', 650);
+  assert.equal(api.saveSession(original), true);
+  const loaded = api.loadSession(original.id);
+  loaded.messages.push({ id: 'message-5', role: 'assistant', content: '碰撞内容不能覆盖未知前缀' });
+  loaded.messages.push({ id: 'unique-tail', role: 'assistant', content: '真正新增的尾部内容' });
+  assert.equal(api.saveSession(loaded), true);
+  const restored = api.loadSession(original.id, { full: true });
+  assert.deepEqual(restored.messages.slice(0, 650), original.messages);
+  assert.equal(restored.messages.length, 651);
+  assert.equal(restored.messages.filter(message => message.id === 'message-5').length, 1);
+  assert.equal(restored.messages.at(-1).id, 'unique-tail');
+});
+
+check('真实归档首屏及恢复仅返回12条并逐页读取650条完整有序历史', dir => {
+  const api = createServerHarness(dir, { fullHistory: false });
+  const original = fixture('bounded-first-screen', 650);
+  assert.equal(api.saveSession(original), true);
+  const loaded = api.loadSession(original.id);
+  assert.equal(loaded.messages.length, 180);
+  const info = api.buildSessionInfoPayload(loaded);
+  assert.equal(info.type, 'session_info');
+  assert.equal(info.messages.length, 12);
+  assert.deepEqual(info.messages, original.messages.slice(638));
+  assert.equal(info.historyTotal, 650);
+  assert.equal(info.historyBaseIndex, 638);
+  assert.equal(info.historyCursor, 638);
+  assert.equal(info.historyTruncated, true);
+  assert.equal(info.historyAvailable, true);
+  api.handleLoadHistoryPage(null, { sessionId: original.id, before: 638, requestId: 'first-earlier-page' });
+  const firstPage = api.responses.at(-1);
+  assert.equal(firstPage.type, 'session_history_chunk');
+  assert.equal(firstPage.messages.length, 24);
+  assert.deepEqual(firstPage.messages, original.messages.slice(614, 638));
+  assert.equal(firstPage.historyTotal, 650);
+  assert.equal(firstPage.historyBaseIndex, 614);
+  assert.equal(firstPage.historyCursor, 614);
+  const older = [...firstPage.messages];
+  let cursor = firstPage.historyCursor;
+  while (cursor > 0) {
+    api.handleLoadHistoryPage(null, { sessionId: original.id, before: cursor, requestId: `complete-page-${cursor}` });
+    const page = api.responses.at(-1);
+    assert.equal(page.type, 'session_history_chunk');
+    assert.equal(page.historyTotal, 650);
+    assert.equal(page.historyAvailable, true);
+    assert(page.messages.length <= 24, '每页消息数必须有界');
+    assert(page.historyCursor < cursor, '历史游标必须前进');
+    older.unshift(...page.messages);
+    cursor = page.historyCursor;
+  }
+  const complete = [...older, ...info.messages];
+  assert.deepEqual(complete, original.messages);
+  assert.equal(new Set(complete.map(message => message.id)).size, 650);
+  api.handleResumeSession({}, { sessionId: original.id, requestId: 'resume-bounded-history' });
+  const resumed = api.responses.at(-1);
+  assert.equal(resumed.type, 'resume_session_result');
+  assert.equal(resumed.messages.length, 12);
+  assert.deepEqual(resumed.messages, info.messages);
+  assert.equal(resumed.historyTotal, info.historyTotal);
+  assert.equal(resumed.historyBaseIndex, info.historyBaseIndex);
+  assert.equal(resumed.historyAvailable, true);
+  assert.equal(resumed.isRunning, false);
+});
+
+check('旧尾部对象协调新增深层元数据后原位修改不污染不可变基线', dir => {
+  const api = createServerHarness(dir, { fullHistory: false });
+  const original = fixture('partial-nested-baseline', 650);
+  assert.equal(api.saveSession(original), true);
+  const streaming = api.loadSession(original.id);
+  const metadata = api.loadSession(original.id, { metadata: true });
+  metadata.nested = { left: 1, right: 1 };
+  assert.equal(api.saveSession(metadata), true);
+  assert.equal(api.saveSession(streaming), true);
+  assert.deepEqual(streaming.nested, { left: 1, right: 1 });
+  const laterMetadata = api.loadSession(original.id, { metadata: true });
+  laterMetadata.nested.right = 2;
+  assert.equal(api.saveSession(laterMetadata), true);
+  streaming.nested.left = 2;
+  assert.equal(api.saveSession(streaming), true);
+  const restored = api.loadSession(original.id, { full: true });
+  assert.deepEqual(restored.nested, { left: 2, right: 2 });
+  assert.deepEqual(streaming.nested, { left: 2, right: 2 });
+  assert.deepEqual(restored.messages, original.messages);
+});
+
+check('中间窗口协调并发尾部提交后再次保存仍保留前后缀', dir => {
+  const api = createServerHarness(dir, { fullHistory: false });
+  const original = fixture('middle-window-rebase', 650);
+  assert.equal(api.saveSession(original), true);
+  const middle = api.loadSession(original.id, { window: { start: 30, end: 33 } });
+  const tail = api.loadSession(original.id);
+  const addedTail = { id: 'concurrent-tail', role: 'assistant', content: '另一运行对象追加的尾部' };
+  tail.messages.push(addedTail);
+  assert.equal(api.saveSession(tail), true);
+  middle.messages[0].content = '中间窗口第一次更新';
+  middle.messages.splice(1, 1);
+  assert.equal(api.saveSession(middle), true);
+  assert.deepEqual(middle.messages.map(message => message.id), ['message-30', 'message-32']);
+  assert.equal(middle.historySnapshotBaseIndex, 30);
+  middle.messages[0].content = '中间窗口第二次更新';
+  middle.messages.splice(1, 0, { id: 'middle-second-insert', role: 'assistant', content: '第二次保存前插内容' });
+  const expected = [...original.messages.slice(0, 30), ...middle.messages, ...original.messages.slice(33), addedTail];
+  assert.equal(api.saveSession(middle), true);
+  assert.deepEqual(api.loadSession(original.id, { full: true }).messages, expected);
+});
+
 if (failures.length > 0) {
   console.error(`完整历史回归失败：${failures.length} 项，已通过 ${checks} 项`);
   process.exitCode = 1;
diff --git a/server.js b/server.js
index 30611b3..e04a568 100644
--- a/server.js
+++ b/server.js
@@ -2377,12 +2377,14 @@ function cleanupExpiredAttachments() {
 
 function collectSessionAttachmentIds(session) {
   const ids = new Set();
-  for (const message of Array.isArray(session?.messages) ? session.messages : []) {
+  const collect = (message) => {
     for (const attachment of Array.isArray(message?.attachments) ? message.attachments : []) {
       const id = sanitizeId(attachment?.id || '');
       if (id) ids.add(id);
     }
-  }
+  };
+  if (sessionHistoryStore.state(session)?.partial) sessionHistoryStore.forEachMessage(session.id, collect);
+  else for (const message of Array.isArray(session?.messages) ? session.messages : []) collect(message);
   return Array.from(ids);
 }
 
@@ -4808,11 +4810,21 @@ function loadNativeSessionHistory(session) {
   }
 }
 
-function resolveSessionHistory(session) {
+function resolveSessionHistory(session, options = {}) {
   const persisted = Array.isArray(session?.messages) ? session.messages : [];
   const persistedMessages = persisted.filter((message) => !isPersistenceNoticeMessage(message));
   const notice = persisted.some(isPersistenceNoticeMessage);
   const historyState = sessionHistoryStore.state(session);
+  if (historyState?.source === 'archive' && (Number.isFinite(options.count) || historyState.partial)) {
+    if (Number.isFinite(options.count)) {
+      const page = sessionHistoryStore.loadHistoryPage(session.id, options.before, options.count);
+      if (!page) throw new Error('完整会话归档已移除');
+      return { ...page, messages: page.messages.map(normalizeHistoryMessage), source: 'archive',
+        available: page.complete, recoverable: false };
+    }
+    return { messages: normalizeArchivedHistory(persistedMessages), total: historyState.total,
+      start: historyState.start, source: 'archive', available: historyState.complete, recoverable: false };
+  }
   if (historyState?.source === 'archive' && historyState.complete) {
     return { messages: normalizeArchivedHistory(persistedMessages), source: 'archive', available: true, recoverable: false };
   }
@@ -6153,7 +6165,7 @@ function refreshSessionSnapshotCache(id) {
     if (fd !== undefined) fs.closeSync(fd);
   }
   if (cachedRevision === revision) return null;
-  const session = loadSession(id);
+  const session = loadSession(id, { count: SESSION_PERSIST_MAX_MESSAGES });
   if (!session) return null;
   const result = buildSessionJsonForPersist({ ...session, historyArchiveRevision: revision });
   try {
@@ -6223,12 +6235,24 @@ function loadSessionMetaFromFile(filePath) {
   }
 }
 
-function loadSession(id) {
+function loadSession(id, options = {}) {
   const normalizedId = sanitizeId(id || '');
   if (!normalizedId) return null;
   try {
     const filePath = sessionPath(normalizedId);
-    let session = sessionHistoryStore.load(normalizedId);
+    // 运行对象仅持有可修改的尾部；完整历史的可信基线是磁盘块引用。
+    let window = options.window;
+    if (options.messageId) {
+      const index = sessionHistoryStore.messageIndex(normalizedId, options.messageId);
+      if (index >= 0) window = { start: index, end: index + 1 };
+    } else if (options.promptId) {
+      const found = sessionHistoryStore.findMessage(normalizedId, message => message?.ccwebPrompt?.id === options.promptId);
+      if (found) window = { start: found.index, end: found.index + 1 };
+    }
+    let session = window ? sessionHistoryStore.loadWindow(normalizedId, window.start, window.end)
+      : options.full === true ? sessionHistoryStore.load(normalizedId)
+      : options.metadata === true ? sessionHistoryStore.loadMetadata(normalizedId)
+        : sessionHistoryStore.loadTail(normalizedId, options.count ?? SESSION_PERSIST_MAX_MESSAGES, { maxBytes: 2 * 1024 * 1024 });
     if (!session) {
       if (!fs.existsSync(filePath)) return null;
       session = safeReadSessionJson(filePath, SESSION_LOAD_MAX_BYTES, { sessionId: normalizedId });
@@ -6248,11 +6272,25 @@ function loadSession(id) {
   }
 }
 
+function findSessionMessage(session, predicate) {
+  const messages = Array.isArray(session?.messages) ? session.messages : [];
+  for (let index = messages.length - 1; index >= 0; index -= 1) {
+    if (predicate(messages[index])) return messages[index];
+  }
+  const historyState = sessionHistoryStore.state(session);
+  if (!historyState?.partial) return null;
+  const found = sessionHistoryStore.findMessage(session.id, (message, index) => (
+    (index < historyState.start || index >= historyState.end) && predicate(message)
+  ));
+  return found?.message || null;
+}
+
 function preserveNewerTaskTrackingForSessionSave(session, targetPath) {
+  // 可信归档的版本保护由同一次存储提交处理，避免保存前重复读取清单。
+  if (sessionHistoryStore.state(session)?.source === 'archive') return;
   let persisted;
   try {
-    persisted = sessionHistoryStore.load(session.id);
-    if (!persisted && fs.existsSync(targetPath)) {
+    if (fs.existsSync(targetPath)) {
       persisted = safeReadSessionJson(targetPath, SESSION_LOAD_MAX_BYTES, { sessionId: session.id });
     }
   } catch {
@@ -6280,9 +6318,13 @@ function saveSession(session, options = {}) {
   const targetPath = sessionPath(session.id);
   try {
     if (!options.taskBoardMetadata) preserveNewerTaskTrackingForSessionSave(session, targetPath);
-    const committed = sessionHistoryStore.save(session);
+    const committed = sessionHistoryStore.save(session, { taskBoardMetadata: options.taskBoardMetadata === true });
+    if (committed.taskTrackingPreserved) plog('INFO', 'task_tracking_preserved_on_session_save', {
+      sessionId: String(session.id || '').slice(0, 8), ...committed.taskTrackingPreserved,
+    });
     try {
-      const result = buildSessionJsonForPersist({ ...committed.session, historyArchiveRevision: committed.revision });
+      const preview = sessionHistoryStore.loadTail(session.id, SESSION_PERSIST_MAX_MESSAGES, { maxBytes: 2 * 1024 * 1024 });
+      const result = buildSessionJsonForPersist({ ...preview, historyArchiveRevision: committed.revision });
       writeFileAtomicSync(targetPath, result.json);
       if (result.guarded) {
         const lastAttempt = result.attempts[result.attempts.length - 1] || {};
@@ -6344,7 +6386,7 @@ function listTaskBoardSessionIds() {
 
 function saveTaskBoardSessionMetadata(session) {
   // 任务服务会克隆会话；重新读取可信档案，只提交它负责的元数据。
-  const completeSession = loadSession(session?.id);
+  const completeSession = loadSession(session?.id, { metadata: true });
   if (!completeSession) return false;
   if (Object.prototype.hasOwnProperty.call(session, 'taskTracking')) {
     completeSession.taskTracking = session.taskTracking;
@@ -6357,7 +6399,7 @@ function saveTaskBoardSessionMetadata(session) {
 
 function createProductionTaskBoardService() {
   const dependencies = {
-    loadSession,
+    loadSession: id => loadSession(id, { metadata: true }),
     saveSession: saveTaskBoardSessionMetadata,
     listSessions: listTaskBoardSessionIds,
     loadStatusDefinitions: loadTaskBoardStatusConfig,
@@ -6990,8 +7032,7 @@ function appendCodexAppRecoveryNotice(sessionId, content) {
   const session = loadSession(sessionId);
   if (!session || !isCodexAppSession(session)) return false;
   // 状态文件按设计会保留证据，重启会再次进入恢复分支；提示只保留一条。
-  if (Array.isArray(session.messages)
-    && session.messages.some(message => message?.codexAppRecoveredPartial === true && message?.content === content)) {
+  if (findSessionMessage(session, message => message?.codexAppRecoveredPartial === true && message?.content === content)) {
     return true;
   }
   session.messages.push({
@@ -7006,8 +7047,7 @@ function appendCodexAppRecoveryNotice(sessionId, content) {
 }
 
 function hasCodexAppTurnMessage(session, turnKey) {
-  return Array.isArray(session?.messages)
-    && session.messages.some((message) => message?.codexAppTurnKey === turnKey);
+  return !!findSessionMessage(session, message => message?.codexAppTurnKey === turnKey);
 }
 
 function recoverCodexAppTurnState(sessionId) {
@@ -8125,7 +8165,7 @@ function startCrossConversationReplyAutoRun(sourceSession, targetSession, replyT
 function hasProcessedCrossConversationReply(session, requestId) {
   const normalizedRequestId = String(requestId || '').trim();
   if (!normalizedRequestId || !Array.isArray(session?.messages)) return false;
-  return session.messages.some((message) => (
+  return !!findSessionMessage(session, (message) => (
     message?.crossConversation?.replyToRequestId === normalizedRequestId &&
     message?.crossConversation?.processed === true
   ));
@@ -8342,7 +8382,8 @@ function getPendingCrossConversationReply(args = {}, sourceSessionId = '') {
   if (!pending || pending.sourceConversationId !== sourceId) {
     const sourceSession = loadSession(sourceId);
     if (hasProcessedCrossConversationReply(sourceSession, requestId)) {
-      const message = sourceSession.messages.find((item) => item?.crossConversation?.replyToRequestId === requestId);
+      const message = findSessionMessage(sourceSession, item => item?.crossConversation?.replyToRequestId === requestId
+        && item?.crossConversation?.processed === true);
       return {
         ok: true,
         requestId,
@@ -8491,17 +8532,15 @@ function completeCrossConversationReply(requestId, entry = {}, targetSession = n
 }
 
 function latestAssistantMessageText(session) {
-  const messages = Array.isArray(session?.messages) ? session.messages : [];
-  for (let index = messages.length - 1; index >= 0; index -= 1) {
-    const message = messages[index];
-    if (message?.role !== 'assistant') continue;
-    const text = extractCrossConversationReplyText(message.content || '');
-    if (text.trim()) return text.trim();
-  }
-  return '';
+  const message = findSessionMessage(session, item => item?.role === 'assistant'
+    && extractCrossConversationReplyText(item.content || '').trim());
+  return message ? extractCrossConversationReplyText(message.content || '').trim() : '';
 }
 
 function assistantMessageCount(session) {
+  if (sessionHistoryStore.state(session)?.source === 'archive') {
+    return sessionHistoryStore.countMessages(session.id, 'assistant');
+  }
   return Array.isArray(session?.messages)
     ? session.messages.filter((message) => message?.role === 'assistant').length
     : 0;
@@ -8682,7 +8721,7 @@ function scriptSelectSemanticBranchApi(args = {}, sourceConversationId = '') {
 function insertJavascriptRunFailureNotice(sourceConversationId, entry = {}) {
   const session = loadSession(sourceConversationId);
   if (!session) return false;
-  if (Array.isArray(session.messages) && session.messages.some((message) => message?.scriptNotification?.runId === entry.runId)) return false;
+  if (findSessionMessage(session, message => message?.scriptNotification?.runId === entry.runId)) return false;
   const reason = entry.terminationReason || entry.signal || `exitCode=${entry.exitCode ?? 'unknown'}`;
   const stderr = String(entry.stderrPreview || '').trim();
   const lines = [
@@ -9218,10 +9257,10 @@ function compactStartMessage(agent) {
 }
 
 function compactDoneMessage(agent) {
-  if (agent === 'codexapp') return '上下文压缩完成。已执行 Codex App 原生 /compact，下次继续在同一会话发送即可。';
+  if (agent === 'codexapp') return '上下文压缩完成。已执行 Codex App 原生 /compact。';
   return agent === 'codex'
-    ? '上下文压缩完成。已执行 Codex /compact，下次继续在同一会话发送即可。'
-    : '上下文压缩完成。已按 Claude Code 原生策略执行 /compact，下次继续在同一会话发送即可。';
+    ? '上下文压缩完成。已执行 Codex /compact。'
+    : '上下文压缩完成。已按 Claude Code 原生策略执行 /compact。';
 }
 
 function initStartMessage(agent) {
@@ -9339,8 +9378,7 @@ function cliRunKey(sessionId, entry = {}) {
 }
 
 function hasCliRunMessage(session, runKey) {
-  return Array.isArray(session?.messages)
-    && session.messages.some(message => message?.role === 'assistant' && message.runKey === runKey);
+  return !!findSessionMessage(session, message => message?.role === 'assistant' && message.runKey === runKey);
 }
 
 function retryTailText(value, maxChars) {
@@ -11534,8 +11572,10 @@ function setCurrentConversationTitle(args = {}, sourceSessionId = '') {
   const changed = previousTitle !== normalizedTitle;
   let titleEvent = null;
   if (changed) {
-    const messageIndex = Array.isArray(session.messages) ? session.messages.length : 0;
-    const anchorMessageIndex = findLatestUserMessageIndex(session.messages);
+    const historyBaseIndex = Number(session.historySnapshotBaseIndex) || 0;
+    const messageIndex = historyBaseIndex + (Array.isArray(session.messages) ? session.messages.length : 0);
+    const localAnchor = findLatestUserMessageIndex(session.messages);
+    const anchorMessageIndex = localAnchor === null ? null : historyBaseIndex + localAnchor;
     titleEvent = {
       title: normalizedTitle,
       changedAt: new Date().toISOString(),
@@ -11611,7 +11651,7 @@ function resolveBranchSource(args = {}) {
   const sourceSessionId = sanitizeId(args.branchSourceSessionId || args.sourceSessionId || '');
   if (!sourceSessionId) return { ok: true, sourceSession: null };
 
-  const sourceSession = loadSession(sourceSessionId);
+  const sourceSession = loadSession(sourceSessionId, { full: true });
   if (!sourceSession) {
     return mcpToolError('branch_source_not_found', '来源会话不存在，无法创建分支。', { sourceSessionId });
   }
@@ -11721,7 +11761,7 @@ function createPersistentConversationSession(args = {}, options = {}) {
 function buildSessionInfoPayload(session) {
   const waitState = crossConversationWaitState(session.id);
   const history = typeof resolveSessionHistory === 'function'
-    ? resolveSessionHistory(session)
+    ? resolveSessionHistory(session, { count: INITIAL_HISTORY_COUNT })
     : { messages: session.messages || [], source: 'snapshot', available: true };
   const messages = sanitizeMessagesForTransport(history.messages || []);
   const taskTracking = taskTrackingSnapshotForSession(session);
@@ -11740,8 +11780,10 @@ function buildSessionInfoPayload(session) {
     totalCost: session.totalCost || 0,
     totalUsage: session.totalUsage || { inputTokens: 0, cachedInputTokens: 0, outputTokens: 0 },
     updated: session.updated,
-    historyTotal: messages.length,
-    historyBaseIndex: 0,
+    historyTotal: history.total ?? messages.length,
+    historyBaseIndex: history.start || 0,
+    historyCursor: history.start || 0,
+    historyTruncated: (history.start || 0) > 0,
     hasUnread: false,
     historyPending: false,
     isRunning: false,
@@ -11822,7 +11864,7 @@ function handleNewSession(ws, msg) {
 
 function handleLoadHistoryPage(ws, msg = {}) {
   const sessionId = sanitizeId(msg.sessionId || '');
-  const session = loadSession(sessionId);
+  const session = loadSession(sessionId, { metadata: true });
   if (!session) {
     return wsSend(ws, attachClientRequestId({
       type: 'error',
@@ -11831,11 +11873,22 @@ function handleLoadHistoryPage(ws, msg = {}) {
       message: 'Session not found',
     }, msg));
   }
+  const requestedBefore = Number.parseInt(String(msg.before || ''), 10);
+  const archived = sessionHistoryStore.state(session);
+  if (archived?.source === 'archive') {
+    const before = Number.isFinite(requestedBefore) ? requestedBefore : Math.max(0, archived.total - INITIAL_HISTORY_COUNT);
+    const page = sessionHistoryStore.loadHistoryPage(session.id, before, HISTORY_CHUNK_SIZE);
+    return wsSend(ws, attachClientRequestId({
+      type: 'session_history_chunk', sessionId: session.id,
+      messages: sanitizeMessagesForTransport(page.messages.map(normalizeHistoryMessage)), remaining: 0,
+      historyCursor: page.start, historyBaseIndex: page.start, historyTruncated: page.start > 0,
+      historyTotal: page.total, historyAvailable: page.complete, historySource: 'archive',
+    }, msg));
+  }
   const history = typeof resolveSessionHistory === 'function'
     ? resolveSessionHistory(session)
     : { messages: session.messages || [], source: 'snapshot', available: true };
-  const list = sanitizeMessagesForTransport(history.messages);
-  const requestedBefore = Number.parseInt(String(msg.before || ''), 10);
+  const list = history.messages;
   const before = Number.isFinite(requestedBefore)
     ? Math.max(0, Math.min(list.length, requestedBefore))
     : Math.max(0, list.length - INITIAL_HISTORY_COUNT);
@@ -11844,7 +11897,7 @@ function handleLoadHistoryPage(ws, msg = {}) {
   wsSend(ws, attachClientRequestId({
     type: 'session_history_chunk',
     sessionId: session.id,
-    messages: list.slice(start, end),
+    messages: sanitizeMessagesForTransport(list.slice(start, end)),
     remaining: 0,
     historyCursor: start,
     historyBaseIndex: start,
@@ -11866,9 +11919,9 @@ function handleMigrateSessionHistory(ws, msg = {}) {
   if (!sessionId || !fs.existsSync(filePath)) return respond({ ok: false, code: 'session_not_found' });
   try {
     const original = fs.readFileSync(filePath, 'utf8');
-    const session = loadSession(sessionId);
+    const session = loadSession(sessionId, { full: true });
     if (!session) return respond({ ok: false, code: 'session_not_found' });
-    if (sessionHistoryStore.state(session)?.complete === true || !session.messages.some(isPersistenceNoticeMessage)) {
+    if (sessionHistoryStore.state(session)?.complete === true) {
       return respond({ ok: true, changed: false, messageCount: session.messages.length });
     }
     const snapshot = session.messages.filter((message) => !isPersistenceNoticeMessage(message));
@@ -11887,7 +11940,7 @@ function handleMigrateSessionHistory(ws, msg = {}) {
     session.messages = merged.messages;
     sessionHistoryStore.markComplete(session);
     if (!saveSession(session)) return respond({ ok: false, code: 'history_archive_save_failed', backupPath });
-    const reloaded = loadSession(sessionId);
+    const reloaded = loadSession(sessionId, { full: true });
     if (!reloaded || reloaded.messages.length !== merged.messages.length) {
       return respond({ ok: false, code: 'history_reload_failed', backupPath });
     }
@@ -11986,7 +12039,7 @@ function attachActiveRuntimeToWs(ws, sessionId, source = {}) {
 
 function handleResumeSession(ws, msg = {}) {
   const sessionId = sanitizeId(msg.sessionId || '');
-  const session = loadSession(sessionId);
+  const session = loadSession(sessionId, { metadata: true });
   if (!session) {
     return wsSend(ws, attachClientRequestId({
       type: 'error',
@@ -12001,7 +12054,7 @@ function handleResumeSession(ws, msg = {}) {
   // 重连只发送 resume_generating 会让前端无法补回断线期间丢掉的历史气泡；
   // 同时带上最近历史，前端可按消息索引幂等补齐而不会重绘整个会话。
   const history = typeof resolveSessionHistory === 'function'
-    ? resolveSessionHistory(session)
+    ? resolveSessionHistory(session, { count: INITIAL_HISTORY_COUNT })
     : { messages: session.messages || [], source: 'snapshot', available: true };
   const historyMessages = sanitizeMessagesForTransport(history.messages || []);
   const recentMessages = historyMessages.slice(-INITIAL_HISTORY_COUNT);
@@ -12016,8 +12069,8 @@ function handleResumeSession(ws, msg = {}) {
     isRunning: isSessionRunning(sessionId),
     attached: hasActiveRuntime,
     messages: recentMessages,
-    historyTotal: historyMessages.length,
-    historyBaseIndex: Math.max(0, historyMessages.length - recentMessages.length),
+    historyTotal: history.total ?? historyMessages.length,
+    historyBaseIndex: (history.start || 0) + Math.max(0, historyMessages.length - recentMessages.length),
     historyAvailable: history.available !== false,
     historySource: history.source || 'snapshot',
   }, msg));
@@ -12028,7 +12081,7 @@ function handleResumeSession(ws, msg = {}) {
 function handleLoadSession(ws, msg) {
   const sessionId = sanitizeId(typeof msg === 'string' ? msg : msg?.sessionId);
   reconcilePendingCrossConversationReplies();
-  const session = loadSession(sessionId);
+  const session = loadSession(sessionId, { metadata: true });
   if (!session) {
     return wsSend(ws, attachClientRequestId({
       type: 'error',
@@ -12038,7 +12091,7 @@ function handleLoadSession(ws, msg) {
     }, msg));
   }
   flushPendingCrossConversationReplies(sessionId);
-  const refreshedSession = loadSession(sessionId) || session;
+  const refreshedSession = loadSession(sessionId, { metadata: true }) || session;
   if (getSessionAgent(refreshedSession) === 'claude' && !refreshedSession.cwd && refreshedSession.claudeSessionId) {
     const localMeta = resolveClaudeSessionLocalMeta(refreshedSession.claudeSessionId);
     if (localMeta?.cwd) {
@@ -12050,20 +12103,27 @@ function handleLoadSession(ws, msg) {
   const requestedTargetMessageIndex = Number.parseInt(String(
     typeof msg === 'object' ? msg?.targetMessageIndex ?? '' : '',
   ), 10);
-  const history = typeof resolveSessionHistory === 'function'
-    ? resolveSessionHistory(refreshedSession)
+  let history = typeof resolveSessionHistory === 'function'
+    ? resolveSessionHistory(refreshedSession, { count: INITIAL_HISTORY_COUNT })
     : { messages: refreshedSession.messages || [], source: 'snapshot', available: true };
+  const historyTotal = history.total ?? history.messages.length;
   const targetMessageIndex = Number.isFinite(requestedTargetMessageIndex)
-    ? Math.max(0, Math.min(history.messages.length - 1, requestedTargetMessageIndex))
+    ? Math.max(0, Math.min(historyTotal - 1, requestedTargetMessageIndex))
     : null;
-  const recentHistoryBaseIndex = Math.max(0, history.messages.length - INITIAL_HISTORY_COUNT);
+  const recentHistoryBaseIndex = Math.max(0, historyTotal - INITIAL_HISTORY_COUNT);
   const targetPrefetchChunks = targetMessageIndex !== null && targetMessageIndex < recentHistoryBaseIndex
     ? Math.ceil((recentHistoryBaseIndex - targetMessageIndex) / HISTORY_CHUNK_SIZE)
     : 0;
-  const { recentMessages, olderChunks, historyRemaining, historyBuffered } = splitHistoryMessages(
+  const prefetchChunks = targetMessageIndex === null ? 0 : Math.min(HISTORY_MAX_CHUNKS_PER_LOAD, Math.max(HISTORY_PREFETCH_CHUNKS, targetPrefetchChunks));
+  if (prefetchChunks > 0 && sessionHistoryStore.state(refreshedSession)?.source === 'archive') {
+    history = resolveSessionHistory(refreshedSession, { count: INITIAL_HISTORY_COUNT + prefetchChunks * HISTORY_CHUNK_SIZE });
+  }
+  const split = splitHistoryMessages(
     history.messages,
-    { prefetchChunks: targetMessageIndex === null ? 0 : Math.max(HISTORY_PREFETCH_CHUNKS, targetPrefetchChunks) },
+    { prefetchChunks },
   );
+  const { recentMessages, olderChunks, historyBuffered } = split;
+  const historyRemaining = (history.start || 0) + split.historyRemaining;
   const effectiveCwd = refreshedSession.cwd || activeProcesses.get(sessionId)?.cwd || activeCodexAppTurns.get(sessionId)?.cwd || null;
   const waitState = crossConversationWaitState(sessionId);
   const taskTracking = taskTrackingSnapshotForSession(refreshedSession);
@@ -12095,10 +12155,10 @@ function handleLoadSession(ws, msg) {
     cwd: effectiveCwd,
     totalCost: session.totalCost || 0,
     totalUsage: session.totalUsage || null,
-    historyTotal: history.messages.length,
+    historyTotal,
     historyBuffered,
     historyCursor: historyRemaining,
-    historyBaseIndex: Math.max(0, history.messages.length - recentMessages.length),
+    historyBaseIndex: Math.max(0, historyTotal - recentMessages.length),
     historyTruncated: historyRemaining > 0,
     historyPending: olderChunks.length > 0,
     historyAvailable: history.available,
@@ -12116,7 +12176,7 @@ function handleLoadSession(ws, msg) {
   }, msg));
 
   if (olderChunks.length > 0) {
-    let chunkEnd = Math.max(0, history.messages.length - recentMessages.length);
+    let chunkEnd = Math.max(0, historyTotal - recentMessages.length);
     olderChunks.forEach((chunk, index) => {
       const chunkStart = Math.max(0, chunkEnd - chunk.length);
       wsSend(ws, attachClientRequestId({
@@ -12127,7 +12187,7 @@ function handleLoadSession(ws, msg) {
         historyCursor: index === olderChunks.length - 1 ? historyRemaining : null,
         historyBaseIndex: chunkStart,
         historyTruncated: historyRemaining > 0,
-        historyTotal: history.messages.length,
+        historyTotal,
         historyAvailable: history.available,
         historySource: history.source,
       }, msg));
@@ -12740,7 +12800,7 @@ function handleMessage(ws, msg, options = {}) {
   if (ws && (options.emitUserMessage || msg.codexAppSteer === true) && persistedUserMessage) {
     wsSend(ws, {
       type: 'session_message', sessionId: currentSessionId, message: persistedUserMessage,
-      messageIndex: session.messages.findIndex((message) => message.id === persistedUserMessage.id),
+      messageIndex: (Number(session.historySnapshotBaseIndex) || 0) + session.messages.findIndex((message) => message.id === persistedUserMessage.id),
     });
   }
   sendSessionList(ws);
@@ -12758,7 +12818,7 @@ function handleMessage(ws, msg, options = {}) {
       wsSend(ws, {
         type: 'codex_app_steer_status', sessionId: currentSessionId,
         clientMessageId: msg.clientMessageId, status: 'sent', message: '已转为新对话',
-        messageIndex: session.messages.findIndex((message) => message.id === persistedUserMessage?.id),
+        messageIndex: (Number(session.historySnapshotBaseIndex) || 0) + session.messages.findIndex((message) => message.id === persistedUserMessage?.id),
       });
       wsSend(ws, buildCodexAppResumePayload(currentSessionId, activeCodexAppTurns.get(currentSessionId)));
     }
@@ -14165,7 +14225,7 @@ function handleCcwebPromptUserResponse(ws, msg = {}) {
     return fail('session_running', '当前会话正在运行，暂不能提交 ccweb 表单答案。');
   }
 
-  const session = loadSession(sessionId);
+  const session = loadSession(sessionId, { promptId });
   if (!session) return fail('session_not_found', '会话不存在。');
 
   const found = findCcwebPromptMessage(session, promptId);
@@ -14227,7 +14287,7 @@ function handleCcwebPromptUserDismiss(ws, msg = {}) {
   if (!sessionId) return fail('missing_session_id', '缺少会话 ID。');
   if (!promptId) return fail('missing_prompt_id', '缺少 promptId。');
 
-  const session = loadSession(sessionId);
+  const session = loadSession(sessionId, { promptId });
   if (!session) return fail('session_not_found', '会话不存在。');
   const found = removeCcwebPromptMessage(session, promptId);
   if (!found) return fail('prompt_not_found', 'ccweb 表单不存在或已被清理。', { promptId });
@@ -15217,7 +15277,7 @@ function handleCodexAppTurnComplete(sessionId, options = {}) {
     }
     const assistantMessage = session?.messages?.find((message) => message.codexAppTurnKey === turnKey);
     const assistantMessageIndex = assistantMessage
-      ? resolveSessionHistory(session).messages.findIndex((message) => message.id === assistantMessage.id)
+      ? sessionHistoryStore.messageIndex(sessionId, assistantMessage.id)
       : -1;
     wsSend(entry.ws, {
       type: 'done', sessionId, costUsd: null, goalActive,
@@ -15266,7 +15326,7 @@ function isCodexAppNoActiveTurnError(err) {
 function rollbackPersistedCodexAppSteerMessage(sessionId, userMessageId) {
   const id = String(userMessageId || '').trim();
   if (!sessionId || !id) return false;
-  const session = loadSession(sessionId);
+  const session = loadSession(sessionId, { messageId: id });
   if (!session || !Array.isArray(session.messages)) return false;
   const nextMessages = session.messages.filter((message) => !(message?.role === 'user' && message.id === id));
   if (nextMessages.length === session.messages.length) return false;
@@ -15294,7 +15354,8 @@ function reorderStaleCodexAppTurnMessages(sessionId, entry, userMessageId) {
   session.updated = new Date().toISOString();
   if (!saveSession(session)) return false;
   wsSend(entry.ws, {
-    type: 'session_message', sessionId, message: sanitizeMessageForTransport(assistantMessage), messageIndex: userIndex,
+    type: 'session_message', sessionId, message: sanitizeMessageForTransport(assistantMessage),
+    messageIndex: (Number(session.historySnapshotBaseIndex) || 0) + userIndex,
   });
   return true;
 }
@@ -15318,7 +15379,8 @@ function handleCodexAppSteerMessage(ws, msg, options = {}) {
     if (clientMessageId) payload.clientMessageId = clientMessageId;
     if (status === 'sent') {
       const savedSession = loadSession(sessionId);
-      payload.messageIndex = savedSession?.messages?.findIndex((message) => message.id === userMessageId);
+      const index = savedSession?.messages?.findIndex((message) => message.id === userMessageId);
+      payload.messageIndex = index >= 0 ? (Number(savedSession.historySnapshotBaseIndex) || 0) + index : index;
     }
     wsSend(targetWs, payload);
   };
@@ -15886,6 +15948,10 @@ function handleListNativeSessions(ws) {
 
 function prepareNativeHistoryImport(existingSession, importedSession) {
   if (!existingSession) return normalizeSession(importedSession);
+  if (sessionHistoryStore.state(existingSession)?.partial) {
+    existingSession = loadSession(existingSession.id, { full: true });
+    if (!existingSession) return null;
+  }
   const snapshot = existingSession.messages.filter(message => !isPersistenceNoticeMessage(message));
   const merged = mergeNativeHistoryWithSnapshot(existingSession, snapshot, importedSession.messages);
   if (!merged.confirmed) return null;