diff --git a/README.md b/README.md
index ad518d6..5f0873e 100644
--- a/README.md
+++ b/README.md
@@ -69,6 +69,20 @@ dsh plugin --profile web add "link:$(pwd)"
 
 插件内置提示段会指导模型按协议执行：建团队 → 按角色拉成员 → 拆任务声明依赖 → 领取并唤醒成员 → 轮询收集产出 → 汇报后删除（归档保留）。
 
+## 存量日志迁移（0.1.0 及更早版本）
+
+0.1.0 及更早版本写入会话日志的 `agent-teams/*` 事件未携带 `ignorable` 标记，导致这些会话在重启后历史无法加载（`SessionFormatUnsupportedError: ... not marked ignorable`）。自 0.1.0 起新写入的事件已不再触发该问题，但**存量会话日志**需要用本仓库提供的迁移工具修复一次：
+
+```sh
+# 找到所有会话日志并原地修补（幂等，可重复执行）
+find "$HOME/.dsh/sessions" -name session.jsonl.zstd   -exec node scripts/migrate-session-logs.mjs {} +
+
+# 或指定单个日志
+node scripts/migrate-session-logs.mjs "$HOME/.dsh/sessions/--Volumes-aigo-work--/session-xxx/session.jsonl.zstd"
+```
+
+工具零依赖（仅 Node 内置 zstd），只给缺失标记的 `agent-teams/*` 事件插入 `"ignorable": true`，其余字节原样保留；执行前建议先备份日志目录。自检：`node scripts/migrate-session-logs.mjs --self-test`。
+
 ## 开发 Skill
 
 仓库按开放 Agent Skills 规范提供 [`dsh-plugin-development`](skills/dsh-plugin-development/SKILL.md)，可直接安装：
diff --git a/scripts/migrate-session-logs.mjs b/scripts/migrate-session-logs.mjs
new file mode 100644
index 0000000..781ca51
--- /dev/null
+++ b/scripts/migrate-session-logs.mjs
@@ -0,0 +1,221 @@
+#!/usr/bin/env node
+/**
+ * migrate-session-logs.mjs
+ *
+ * Repair DeepSeek Harness session logs written by dsh-agent-teams builds that
+ * omitted the `ignorable` envelope marker (0.1.0 and earlier, and any local
+ * build before the fix). The harness's persistence coordinator refuses to
+ * interpret a log containing an event type outside its generated vocabulary
+ * unless the event carries `"ignorable": true`; such logs fail with:
+ *
+ *   SessionFormatUnsupportedError: ... contains event type "agent-teams/..." ...
+ *   unknown to this harness and not marked ignorable; refusing to interpret
+ *   the log
+ *
+ * This tool rewrites each log in place: it decodes every Zstandard frame,
+ * inserts `"ignorable": true` into each `agent-teams/*` event that lacks it
+ * (all other bytes are preserved), and re-encodes the log as a header frame
+ * plus one body frame using Node's own zstd implementation (checksummed,
+ * matching the harness writer). It is idempotent: a second run changes
+ * nothing.
+ *
+ * Usage:
+ *   node scripts/migrate-session-logs.mjs <session.jsonl.zstd> [more logs...]
+ *
+ * Logs live under `$DSH_HOME/sessions/<project-dir>/<session-id>/`:
+ *   find "$HOME/.dsh/sessions" -name session.jsonl.zstd \
+ *     -exec node scripts/migrate-session-logs.mjs {} +
+ *
+ * Zero dependencies — Node.js >= 22.19 with built-in zstd support.
+ */
+import { readFile, rename, writeFile } from 'node:fs/promises'
+import { constants, zstdCompress, zstdDecompress } from 'node:zlib'
+import { promisify } from 'node:util'
+
+const compressFrame = promisify(zstdCompress)
+const decompressFrame = promisify(zstdDecompress)
+
+const ZSTD_MAGIC = 0xFD2FB528
+
+/**
+ * Locate complete Zstandard frames in a concatenated stream (the layout the
+ * harness's JSONL backend writes: one independently decodable frame per
+ * append batch). A structurally incomplete final frame is an error here:
+ * migrate only logs whose committed prefix is whole.
+ * @param buffer - the complete log bytes.
+ * @returns byte ranges of every frame.
+ */
+export function scanFrames(buffer) {
+  const frames = []
+  let offset = 0
+  while (offset < buffer.length) {
+    const start = offset
+    if (buffer.length - offset < 4) throw new Error(`torn frame at byte ${offset}`)
+    if (buffer.readUInt32LE(offset) !== ZSTD_MAGIC) {
+      throw new Error(`invalid frame magic at byte ${offset}`)
+    }
+    offset += 4
+    if (offset === buffer.length) throw new Error('torn frame (header missing)')
+    const descriptor = buffer.readUInt8(offset)
+    offset += 1
+    if ((descriptor & 0x18) !== 0) throw new Error('reserved frame-header bit')
+    const contentSizeFlag = descriptor >>> 6
+    const singleSegment = (descriptor & 0x20) !== 0
+    const checksum = (descriptor & 0x04) !== 0
+    const dictionaryFlag = descriptor & 0x03
+    const dictionaryBytes = dictionaryFlag === 3 ? 4 : dictionaryFlag
+    const contentSizeBytes = contentSizeFlag === 0
+      ? (singleSegment ? 1 : 0)
+      : 1 << contentSizeFlag
+    const remainingHeaderBytes = (singleSegment ? 0 : 1) + dictionaryBytes + contentSizeBytes
+    if (buffer.length - offset < remainingHeaderBytes) throw new Error('torn frame header')
+    offset += remainingHeaderBytes
+    for (;;) {
+      if (buffer.length - offset < 3) throw new Error('torn block header')
+      const blockHeader = buffer.readUIntLE(offset, 3)
+      offset += 3
+      const lastBlock = (blockHeader & 1) !== 0
+      const blockType = (blockHeader >>> 1) & 0x03
+      const blockSize = blockHeader >>> 3
+      if (blockType === 0x03) throw new Error('reserved block type')
+      const payloadBytes = blockType === 0x01 ? 1 : blockSize
+      if (buffer.length - offset < payloadBytes) throw new Error('torn block payload')
+      offset += payloadBytes
+      if (lastBlock) break
+    }
+    if (checksum) {
+      if (buffer.length - offset < 4) throw new Error('torn checksum')
+      offset += 4
+    }
+    frames.push({ start, end: offset })
+  }
+  return frames
+}
+
+/**
+ * Decode a complete concatenated stream to its plaintext.
+ * @param buffer - the log bytes.
+ * @param frames - frame ranges from {@link scanFrames}.
+ * @returns the decoded UTF-8 text.
+ */
+export async function decodeLog(buffer, frames) {
+  const parts = []
+  for (const frame of frames) {
+    const plain = await decompressFrame(buffer.subarray(frame.start, frame.end))
+    parts.push(plain)
+  }
+  return Buffer.concat(parts).toString('utf8')
+}
+
+/**
+ * Insert `"ignorable": true` into every `agent-teams/*` event line lacking
+ * the marker, preserving every other byte.
+ * @param text - the decoded log text.
+ * @returns the patched text and how many events changed.
+ */
+export function patchAgentTeamsEvents(text) {
+  const lines = text.split('\n')
+  let patched = 0
+  for (let i = 0; i < lines.length; i++) {
+    const line = lines[i]
+    if (!line.startsWith('{"type":"agent-teams/')) continue
+    if (line.includes('"ignorable"')) continue
+    const match = /^\{"type":"(agent-teams\/[^"]+)"(.*)$/.exec(line)
+    if (!match) continue
+    lines[i] = `{"type":"${match[1]}","ignorable":true${match[2]}`
+    patched += 1
+  }
+  return { text: lines.join('\n'), patched }
+}
+
+/**
+ * Re-encode a log as a header frame plus one body frame (the same container
+ * shape the harness reads; the JSONL backend accepts any frame layout).
+ * @param text - the full log text (header line first).
+ * @returns the encoded log bytes.
+ */
+export async function encodeLog(text) {
+  const newline = text.indexOf('\n')
+  if (newline === -1) throw new Error('log has no header line')
+  const header = text.slice(0, newline + 1)
+  const body = text.slice(newline + 1)
+  const options = { params: { [constants.ZSTD_c_checksumFlag]: 1 } }
+  const headerFrame = await compressFrame(header, options)
+  const bodyFrame = await compressFrame(body, options)
+  return Buffer.concat([headerFrame, bodyFrame])
+}
+
+/**
+ * Migrate one log file in place. Idempotent: a log with no unmarked
+ * `agent-teams/*` events is left untouched.
+ * @param path - absolute path to a `session.jsonl.zstd` log.
+ * @returns how many events were patched.
+ */
+export async function migrateLog(path) {
+  const buffer = await readFile(path)
+  const frames = scanFrames(buffer)
+  if (frames.length === 0) throw new Error(`${path}: no frames`)
+  const text = await decodeLog(buffer, frames)
+  const { text: patchedText, patched } = patchAgentTeamsEvents(text)
+  if (patched === 0) return 0
+  const encoded = await encodeLog(patchedText)
+  const tmp = `${path}.migrate-tmp`
+  await writeFile(tmp, encoded)
+  await rename(tmp, path)
+  return patched
+}
+
+/**
+ * In-memory self test: build a synthetic log containing unmarked
+ * `agent-teams/*` events, migrate it, and assert the markers landed while
+ * every other line stayed byte-identical.
+ */
+async function selfTest() {
+  const assert = (condition, message) => {
+    if (!condition) throw new Error(`self-test failed: ${message}`)
+  }
+  const header = '{"type":"session","version":0,"id":"session-test","createdAt":1,"cwd":"/tmp"}\n'
+  const event = '{"type":"agent-teams/task-created","seq":5,"time":2,"data":{"teamId":"t"}}'
+  const plain = { type: 'user/message', seq: 6, time: 3, data: { content: [] } }
+  const untouched = JSON.stringify(plain)
+  const body = `${event}\n${untouched}\n`
+  const encoded = await encodeLog(header + body)
+  const migrated = await migrateString(encoded)
+  assert(migrated.includes('"ignorable":true'), 'marker not inserted')
+  assert(migrated.includes(untouched), 'non-agent-teams line changed')
+  assert(migrated.includes(header), 'header changed')
+  const { patched } = patchAgentTeamsEvents(migrated)
+  assert(patched === 0, 'second pass should be a no-op')
+  console.log('self-test OK')
+}
+
+/** Migrate an in-memory log buffer, returning the patched plaintext. */
+async function migrateString(buffer) {
+  const frames = scanFrames(buffer)
+  const text = await decodeLog(buffer, frames)
+  const { text: patchedText } = patchAgentTeamsEvents(text)
+  return patchedText
+}
+
+const files = process.argv.slice(2)
+if (files.length === 1 && files[0] === '--self-test') {
+  await selfTest()
+  process.exit(0)
+}
+if (files.length === 0) {
+  console.error('usage: node scripts/migrate-session-logs.mjs <session.jsonl.zstd> [...]')
+  console.error('       node scripts/migrate-session-logs.mjs --self-test')
+  process.exit(2)
+}
+let total = 0
+for (const file of files) {
+  try {
+    const patched = await migrateLog(file)
+    total += patched
+    console.log(`${patched > 0 ? 'patched' : 'clean  '} ${patched} event(s): ${file}`)
+  } catch (error) {
+    console.error(`FAILED ${file}: ${error.message}`)
+    process.exitCode = 1
+  }
+}
+console.log(`done: ${total} event(s) patched across ${files.length} log(s)`)