fix(persistence): preserve subagent session origin

examples/acp-agent/tests/snapshots/advanced-toolchain/session.1.jsonl

@@ -1,4 +1,4 @@
-{"type":"session","version":0,"id":"22222222-2222-4222-8222-222222222222","createdAt":1783950001000,"cwd":"{{cwd}}","parentSession":"11111111-1111-4111-8111-111111111111","delegationDepth":1}
+{"type":"session","version":0,"id":"22222222-2222-4222-8222-222222222222","createdAt":1783950001000,"cwd":"{{cwd}}","parentSession":"11111111-1111-4111-8111-111111111111","origin":"subagent","delegationDepth":1}
 {"type":"turn/start","seq":0,"time":1783957884563,"data":{"turn":1,"trigger":{"kind":"message","source":{"kind":"user"}}}}
 {"type":"user/message","seq":1,"time":1783957884563,"data":{"content":[{"type":"text","text":"Reply with exactly DIRECT_CHILD_OK and nothing else."}],"source":{"kind":"user"},"role":"user","id":"9769d9fc-4aef-45ae-bea7-dfa1697971ef"},"surfaceOp":"append"}
 {"type":"session/title","seq":2,"time":1783957884563,"data":{"title":"Reply with exactly DIRECT_CHILD_OK and","messageSeqs":[1],"source":{"kind":"fallback"}}}

examples/acp-agent/tests/snapshots/advanced-toolchain/session.2.jsonl

@@ -1,4 +1,4 @@
-{"type":"session","version":0,"id":"33333333-3333-4333-8333-333333333333","createdAt":1783950002000,"cwd":"{{cwd}}","parentSession":"11111111-1111-4111-8111-111111111111","delegationDepth":1}
+{"type":"session","version":0,"id":"33333333-3333-4333-8333-333333333333","createdAt":1783950002000,"cwd":"{{cwd}}","parentSession":"11111111-1111-4111-8111-111111111111","origin":"subagent","delegationDepth":1}
 {"type":"turn/start","seq":0,"time":1783957884700,"data":{"turn":1,"trigger":{"kind":"message","source":{"kind":"user"}}}}
 {"type":"user/message","seq":1,"time":1783957884700,"data":{"content":[{"type":"text","text":"Reply with exactly WORKFLOW_CHILD_OK and nothing else."}],"source":{"kind":"user"},"role":"user","id":"a9ccad1e-ded5-4f5f-9419-a6bc440e96c3"},"surfaceOp":"append"}
 {"type":"session/title","seq":2,"time":1783957884700,"data":{"title":"Reply with exactly WORKFLOW_CHILD_OK and","messageSeqs":[1],"source":{"kind":"fallback"}}}

examples/acp-agent/tests/snapshots/subagent-continuable/session.1.jsonl

@@ -1,4 +1,4 @@
-{"type":"session","version":0,"id":"33333333-3333-4333-8333-333333333333","createdAt":1789000001000,"cwd":"{{cwd}}","parentSession":"11111111-1111-4111-8111-111111111111","delegationDepth":1}
+{"type":"session","version":0,"id":"33333333-3333-4333-8333-333333333333","createdAt":1789000001000,"cwd":"{{cwd}}","parentSession":"11111111-1111-4111-8111-111111111111","origin":"subagent","delegationDepth":1}
 {"type":"subagent/descriptor","seq":0,"time":1785544945198,"data":{"version":2,"mode":"continuable","provider":"spawn","label":"Reply with CHILD_OK","agentProvider":"deepseek-official","agentModel":"deepseek-v4-flash"}}
 {"type":"session/end-seed","seq":1,"time":1785544945198,"data":{}}
 {"type":"turn/start","seq":2,"time":1785544945199,"data":{"turn":1,"trigger":{"kind":"message","source":{"kind":"user"}}}}

examples/acp-agent/tests/snapshots/subagent-depth-two-rejection/session.1.jsonl

@@ -1,4 +1,4 @@
-{"type":"session","version":0,"id":"22222222-2222-4222-8222-222222222222","createdAt":1001,"cwd":"{{cwd}}","parentSession":"11111111-1111-4111-8111-111111111111","delegationDepth":1}
+{"type":"session","version":0,"id":"22222222-2222-4222-8222-222222222222","createdAt":1001,"cwd":"{{cwd}}","parentSession":"11111111-1111-4111-8111-111111111111","origin":"subagent","delegationDepth":1}
 {"type":"turn/start","seq":0,"time":1784540790312,"data":{"turn":1,"trigger":{"kind":"message","source":{"kind":"user"}}}}
 {"type":"user/message","seq":1,"time":1784540790312,"data":{"content":[{"type":"text","text":"Call subagent once. Ask that child to attempt one further subagent call, then report the result."}],"source":{"kind":"user"},"role":"user","id":"9cf268f7-2c64-4344-8512-dc9cb4dc66d4"},"surfaceOp":"append"}
 {"type":"session/title","seq":2,"time":1784540790312,"data":{"title":"Call subagent once. Ask that","messageSeqs":[1],"source":{"kind":"fallback"}}}

examples/acp-agent/tests/snapshots/subagent-depth-two-rejection/session.2.jsonl

@@ -1,4 +1,4 @@
-{"type":"session","version":0,"id":"33333333-3333-4333-8333-333333333333","createdAt":1002,"cwd":"{{cwd}}","parentSession":"22222222-2222-4222-8222-222222222222","delegationDepth":2}
+{"type":"session","version":0,"id":"33333333-3333-4333-8333-333333333333","createdAt":1002,"cwd":"{{cwd}}","parentSession":"22222222-2222-4222-8222-222222222222","origin":"subagent","delegationDepth":2}
 {"type":"turn/start","seq":0,"time":1784540790319,"data":{"turn":1,"trigger":{"kind":"message","source":{"kind":"user"}}}}
 {"type":"user/message","seq":1,"time":1784540790319,"data":{"content":[{"type":"text","text":"Attempt one subagent call beyond the configured cap, then report the rejection."}],"source":{"kind":"user"},"role":"user","id":"17f4fd95-842c-4c48-90d9-cdd04456687f"},"surfaceOp":"append"}
 {"type":"session/title","seq":2,"time":1784540790319,"data":{"title":"Attempt one subagent call beyond","messageSeqs":[1],"source":{"kind":"fallback"}}}

examples/acp-agent/tests/snapshots/subagent-fork/session.1.jsonl

@@ -1,4 +1,4 @@
-{"type":"session","version":0,"id":"ada8966c-9fa3-441b-8721-37ff1e795e6a","createdAt":1783352137161,"cwd":"{{cwd}}","parentSession":"96cf59c9-b347-48b9-b234-a5200913ad05","seedLength":40,"delegationDepth":1}
+{"type":"session","version":0,"id":"ada8966c-9fa3-441b-8721-37ff1e795e6a","createdAt":1783352137161,"cwd":"{{cwd}}","parentSession":"96cf59c9-b347-48b9-b234-a5200913ad05","seedLength":40,"origin":"subagent","delegationDepth":1}
 {"type":"turn/start","seq":0,"time":1783352134837,"data":{"turn":1,"trigger":{"kind":"message","source":{"kind":"user"}}}}
 {"type":"user/message","seq":1,"time":1783352134838,"data":{"content":[{"type":"text","text":"Remember this fact for later: the project codeword is MARMALADE. Reply with the single word OK and stop. Do not use any tools."}],"source":{"kind":"user"},"role":"user","id":"181ef004-8be2-416c-a223-3ff7f99cc79c"},"surfaceOp":"append"}
 {"type":"session/title","seq":2,"time":1783352134838,"data":{"title":"Remember this fact for later:","messageSeqs":[1],"source":{"kind":"fallback"}}}

examples/acp-agent/tests/snapshots/subagent-list-agents/session.1.jsonl

@@ -1,4 +1,4 @@
-{"type":"session","version":0,"id":"33333333-3333-4333-8333-333333333333","createdAt":1789000001000,"cwd":"{{cwd}}","parentSession":"11111111-1111-4111-8111-111111111111","delegationDepth":1}
+{"type":"session","version":0,"id":"33333333-3333-4333-8333-333333333333","createdAt":1789000001000,"cwd":"{{cwd}}","parentSession":"11111111-1111-4111-8111-111111111111","origin":"subagent","delegationDepth":1}
 {"type":"subagent/descriptor","seq":0,"time":1785531795641,"data":{"version":2,"mode":"continuable","provider":"spawn","label":"Reply with CHILD_OK","agentProvider":"deepseek-official","agentModel":"deepseek-v4-flash"}}
 {"type":"session/end-seed","seq":1,"time":1785531795641,"data":{}}
 {"type":"turn/start","seq":2,"time":1785531795641,"data":{"turn":1,"trigger":{"kind":"message","source":{"kind":"user"}}}}

examples/acp-agent/tests/snapshots/subagent-mixed/session.1.jsonl

@@ -1,4 +1,4 @@
-{"type":"session","version":0,"id":"e4aafa18-b9e3-48d0-8aae-6c9b25dcae80","createdAt":1783352145223,"cwd":"{{cwd}}","parentSession":"959ffdf5-03e2-465e-9482-009b704632dc","delegationDepth":1}
+{"type":"session","version":0,"id":"e4aafa18-b9e3-48d0-8aae-6c9b25dcae80","createdAt":1783352145223,"cwd":"{{cwd}}","parentSession":"959ffdf5-03e2-465e-9482-009b704632dc","origin":"subagent","delegationDepth":1}
 {"type":"turn/start","seq":0,"time":1783352145224,"data":{"turn":1,"trigger":{"kind":"message","source":{"kind":"user"}}}}
 {"type":"user/message","seq":1,"time":1783352145224,"data":{"content":[{"type":"text","text":"Reply with exactly the word ALPHA and nothing else."}],"source":{"kind":"user"},"role":"user","id":"ad85672f-96fe-4462-a2c7-0411ab9c92c2"},"surfaceOp":"append"}
 {"type":"session/title","seq":2,"time":1783352145224,"data":{"title":"Reply with exactly the word","messageSeqs":[1],"source":{"kind":"fallback"}}}

examples/acp-agent/tests/snapshots/subagent-mixed/session.2.jsonl

@@ -1,4 +1,4 @@
-{"type":"session","version":0,"id":"02b3a8dd-1d5e-4866-825f-5fbf5000a632","createdAt":1783352147504,"cwd":"{{cwd}}","parentSession":"959ffdf5-03e2-465e-9482-009b704632dc","seedLength":34,"delegationDepth":1}
+{"type":"session","version":0,"id":"02b3a8dd-1d5e-4866-825f-5fbf5000a632","createdAt":1783352147504,"cwd":"{{cwd}}","parentSession":"959ffdf5-03e2-465e-9482-009b704632dc","seedLength":34,"origin":"subagent","delegationDepth":1}
 {"type":"turn/start","seq":0,"time":1783352142834,"data":{"turn":1,"trigger":{"kind":"message","source":{"kind":"user"}}}}
 {"type":"user/message","seq":1,"time":1783352142834,"data":{"content":[{"type":"text","text":"Remember this fact for later: the project codeword is SAFFRON. Reply with the single word OK and stop. Do not use any tools."}],"source":{"kind":"user"},"role":"user","id":"7d598287-d208-4f2d-a97b-66f397094c6c"},"surfaceOp":"append"}
 {"type":"session/title","seq":2,"time":1783352142834,"data":{"title":"Remember this fact for later:","messageSeqs":[1],"source":{"kind":"fallback"}}}

examples/acp-agent/tests/snapshots/subagent-multi/session.1.jsonl

@@ -1,4 +1,4 @@
-{"type":"session","version":0,"id":"553f8e92-aac1-4df3-8657-eacbb58f9581","createdAt":1783352127669,"cwd":"{{cwd}}","parentSession":"14dda109-5728-45ba-a002-7db9543fe50e","delegationDepth":1}
+{"type":"session","version":0,"id":"553f8e92-aac1-4df3-8657-eacbb58f9581","createdAt":1783352127669,"cwd":"{{cwd}}","parentSession":"14dda109-5728-45ba-a002-7db9543fe50e","origin":"subagent","delegationDepth":1}
 {"type":"turn/start","seq":0,"time":1783352127670,"data":{"turn":1,"trigger":{"kind":"message","source":{"kind":"user"}}}}
 {"type":"user/message","seq":1,"time":1783352127670,"data":{"content":[{"type":"text","text":"Reply with exactly the word ALPHA and nothing else."}],"source":{"kind":"user"},"role":"user","id":"78174c9e-c9f2-4c05-8dc4-12108419e6ad"},"surfaceOp":"append"}
 {"type":"session/title","seq":2,"time":1783352127670,"data":{"title":"Reply with exactly the word","messageSeqs":[1],"source":{"kind":"fallback"}}}

examples/acp-agent/tests/snapshots/subagent-multi/session.2.jsonl

@@ -1,4 +1,4 @@
-{"type":"session","version":0,"id":"5f49e80c-16fc-42c7-a617-0b6bd0680aa3","createdAt":1783352129662,"cwd":"{{cwd}}","parentSession":"14dda109-5728-45ba-a002-7db9543fe50e","delegationDepth":1}
+{"type":"session","version":0,"id":"5f49e80c-16fc-42c7-a617-0b6bd0680aa3","createdAt":1783352129662,"cwd":"{{cwd}}","parentSession":"14dda109-5728-45ba-a002-7db9543fe50e","origin":"subagent","delegationDepth":1}
 {"type":"turn/start","seq":0,"time":1783352129662,"data":{"turn":1,"trigger":{"kind":"message","source":{"kind":"user"}}}}
 {"type":"user/message","seq":1,"time":1783352129662,"data":{"content":[{"type":"text","text":"Reply with exactly the word BETA and nothing else."}],"source":{"kind":"user"},"role":"user","id":"9542fa06-afea-4f6d-9db1-b6848def4bc7"},"surfaceOp":"append"}
 {"type":"session/title","seq":2,"time":1783352129662,"data":{"title":"Reply with exactly the word","messageSeqs":[1],"source":{"kind":"fallback"}}}

examples/acp-agent/tests/snapshots/subagent-spawn/session.1.jsonl

@@ -1,4 +1,4 @@
-{"type":"session","version":0,"id":"ea339828-7885-42e1-9083-4355e6f1708d","createdAt":1783352120855,"cwd":"{{cwd}}","parentSession":"5138ed0d-e86e-4a7d-b75b-803307e92b17","delegationDepth":1}
+{"type":"session","version":0,"id":"ea339828-7885-42e1-9083-4355e6f1708d","createdAt":1783352120855,"cwd":"{{cwd}}","parentSession":"5138ed0d-e86e-4a7d-b75b-803307e92b17","origin":"subagent","delegationDepth":1}
 {"type":"turn/start","seq":0,"time":1783352120856,"data":{"turn":1,"trigger":{"kind":"message","source":{"kind":"user"}}}}
 {"type":"user/message","seq":1,"time":1783352120856,"data":{"content":[{"type":"text","text":"Reply with exactly the word CHILD_OK and nothing else."}],"source":{"kind":"user"},"role":"user","id":"c7b8251e-05a6-48da-b7e1-00612d1679a4"},"surfaceOp":"append"}
 {"type":"session/title","seq":2,"time":1783352120856,"data":{"title":"Reply with exactly the word","messageSeqs":[1],"source":{"kind":"fallback"}}}

examples/acp-agent/tests/snapshots/workflow-run/session.1.jsonl

@@ -1,4 +1,4 @@
-{"type":"session","version":0,"id":"583a4db2-3350-436c-b4a5-5615fd159052","createdAt":1783600636316,"cwd":"{{cwd}}","parentSession":"3fd7d599-56b1-493a-930d-f1fc5e1556e8","delegationDepth":1}
+{"type":"session","version":0,"id":"583a4db2-3350-436c-b4a5-5615fd159052","createdAt":1783600636316,"cwd":"{{cwd}}","parentSession":"3fd7d599-56b1-493a-930d-f1fc5e1556e8","origin":"subagent","delegationDepth":1}
 {"type":"turn/start","seq":0,"time":1783600636316,"data":{"turn":1,"trigger":{"kind":"message","source":{"kind":"user"}}}}
 {"type":"user/message","seq":1,"time":1783600636316,"data":{"content":[{"type":"text","text":"Reply with exactly the word WF_CHILD_OK and nothing else."}],"source":{"kind":"user"},"role":"user","id":"a7990b4d-9b1d-47de-883b-47f6755c2b9b"},"surfaceOp":"append"}
 {"type":"session/title","seq":2,"time":1783600636316,"data":{"title":"Reply with exactly the word","messageSeqs":[1],"source":{"kind":"fallback"}}}

examples/headless-agent/tests/subagent-inheritance-snapshots/parent-override/child.expected.jsonl

@@ -1,4 +1,4 @@
-{"type":"session","version":0,"id":"{{sessionId}}","createdAt":0,"cwd":"{{cwd}}","parentSession":"{{sessionId}}","delegationDepth":1}
+{"type":"session","version":0,"id":"{{sessionId}}","createdAt":0,"cwd":"{{cwd}}","parentSession":"{{sessionId}}","origin":"subagent","delegationDepth":1}
 {"type":"sandbox/mode","seq":0,"time":0,"data":{"mode":"read-only","source":"delegation"}}
 {"type":"turn/start","seq":1,"time":0,"data":{"turn":1,"trigger":{"kind":"message","source":{"kind":"user"}}}}
 {"type":"user/message","seq":2,"time":0,"data":{"content":[{"type":"text","text":"Use the write tool exactly once with file_path set to exactly the relative path inherited.txt and content escaped. If the write is denied, reply with the single word CHILD_DENIED and the denial marker line; do not retry and do not request escalation. If it succeeds, reply CHILD_WROTE."}],"source":{"kind":"user"},"role":"user","id":"{{sessionId}}"},"surfaceOp":"append"}

examples/jsonrpc-agent/tests/snapshots/subagent-spawn/session.1.jsonl

@@ -1,4 +1,4 @@
-{"type":"session","version":0,"id":"0b7fd85c-9f6f-4d46-b954-363984ce66fb","createdAt":1785097410282,"cwd":"{{cwd}}","parentSession":"sdk-snapshot-subagent","delegationDepth":1}
+{"type":"session","version":0,"id":"0b7fd85c-9f6f-4d46-b954-363984ce66fb","createdAt":1785097410282,"cwd":"{{cwd}}","parentSession":"sdk-snapshot-subagent","origin":"subagent","delegationDepth":1}
 {"type":"turn/start","seq":0,"time":1785097410283,"data":{"turn":1,"trigger":{"kind":"message","source":{"kind":"user"}}}}
 {"type":"user/message","seq":1,"time":1785097410283,"data":{"content":[{"type":"text","text":"Reply with exactly: child answer 42."}],"source":{"kind":"user"},"role":"user","id":"b33e0611-0483-44a9-8b57-9828b87cb846"},"surfaceOp":"append"}
 {"type":"session/title","seq":2,"time":1785097410283,"data":{"title":"Reply with exactly: child answer","messageSeqs":[1],"source":{"kind":"fallback"}}}

packages/session-persistence/session-persistence-jsonl/README.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write packages/session-persistence/session-persistence-jsonl/README.md
-README.md: ab6ecd28f12bd167aeac789d1565705e167d60f4
-README.zh.md: 16e0afa98c08710d298aa1487ddd8e51e1dc55c9
+README.md: 0f243a568a55641ded1cb6131804e77093df6af1
+README.zh.md: ae3c84e51e47edb33abbada43ec72c4d62b5a432

packages/session-persistence/session-persistence-jsonl/README.md

@@ -14,7 +14,7 @@ The JSONL durable session-persistence backend — a concrete `SessionPersistence
       session.jsonl              # only with compression: 'none'
 ```
 
-- The first logical line is the immutable `SessionHeader` tagged `{ type: 'session', version, id, cwd?, createdAt, parentSession?, seedLength?, delegationDepth }`. `delegationDepth` is required on disk and is `0` for a top-level session; a missing or invalid value rejects the log. Every subsequent logical line is one storage record; `assistant/chunk` events are never dropped, and `seq` stays contiguous across the decoded log (`events[i].seq === i`).
+- The first logical line is the immutable `SessionHeader` tagged `{ type: 'session', version, id, cwd?, createdAt, parentSession?, seedLength?, origin?, delegationDepth }`. `delegationDepth` is required on disk and is `0` for a top-level session; a missing or invalid value rejects the log. Every subsequent logical line is one storage record; `assistant/chunk` events are never dropped, and `seq` stays contiguous across the decoded log (`events[i].seq === i`).
 - A storage record is a `SessionEvent` JSON verbatim, or — for an eligible run when `packChunks` is enabled — a **packed chunk row** (`text-chunks` / `reasoning-chunks` / `tool-call-chunks`; bare slash-less tags like the header's `session`, so row tags cannot be confused with event types): one line holding a run of ≥3 consecutive same-block `assistant/chunk` delta events, `seq0`/`time0` plus per-member `dt` gaps reconstructing every member's `seq`/`time` exactly. The lossless codec lives in `@deepseek-ai/dsh-session` (`packChunkRuns`/`decodeStorageRecord`) and whitelists exact shapes — anything unrecognized stores verbatim. Reading is layout-blind: `load` always decodes rows, so packed, unpacked, and mixed files load identically.
 - The project directory keeps the normalized cwd readable for navigation and is bounded for filesystem component limits. Separator replacement and truncation are intentionally lossy, so cwd strings that normalize alike share a project directory; session ids still select distinct session directories. On a case-insensitive filesystem, identity validation accepts an alternate path spelling only when filesystem canonicalization resolves both spellings to the same transcript. The configured root remains deployment-controlled: it may be project-local, shared, temporary, or centralized. The [project-session directory decision](../../../.agents/notes/implemented/architecture/2026-07-24-project-session-directories.md) records this tradeoff.
 - Session ids are unvalidated branded strings, so they are injectively escaped to a single safe path segment before use (no traversal, no collision). The resulting directory is reserved for additional session-owned artifacts; discovery reads only the fixed transcript filename.

packages/session-persistence/session-persistence-jsonl/README.zh.md

@@ -14,7 +14,7 @@ JSONL 持久会话存储后端：`SessionPersistence` 的一个具体实现（`d
       session.jsonl              # only with compression: 'none'
 ```
 
-- 第一个逻辑行是不可变的 `SessionHeader`，标记为 `{ type: 'session', version, id, cwd?, createdAt, parentSession?, seedLength?, delegationDepth }`。`delegationDepth` 在磁盘上必需，顶层会话为 `0`；缺失或无效值会拒绝日志。后续每个逻辑行是一条存储记录；`assistant/chunk` 事件绝不丢弃，且 `seq` 在解码日志中保持连续（`events[i].seq === i`）。
+- 第一个逻辑行是不可变的 `SessionHeader`，标记为 `{ type: 'session', version, id, cwd?, createdAt, parentSession?, seedLength?, origin?, delegationDepth }`。`delegationDepth` 在磁盘上必需，顶层会话为 `0`；缺失或无效值会拒绝日志。后续每个逻辑行是一条存储记录；`assistant/chunk` 事件绝不丢弃，且 `seq` 在解码日志中保持连续（`events[i].seq === i`）。
 - 存储记录是原样 `SessionEvent` JSON，或在 `packChunks` 已启用且连续段符合条件时写入的**打包分片行**（`text-chunks` / `reasoning-chunks` / `tool-call-chunks`；像 header 的 `session` 一样不带斜杠，因此行 tag 不会与事件类型混淆）：一行保存至少 3 个连续同 block `assistant/chunk` delta 事件，`seq0`/`time0` 和每成员 `dt` 间隔精确重建每个成员的 `seq`/`time`。无损 codec 位于 `@deepseek-ai/dsh-session`（`packChunkRuns`/`decodeStorageRecord`），并使用精确形态 allowlist：任何未识别内容原样存储。读取与布局无关：`load` 始终解码行，因此打包、非打包和混合文件加载结果一致。
 - 项目目录保留规范化 cwd 可读，并限制在文件系统组件上限内。分隔符替换和截断刻意有损，因此规范化相同的 cwd 字符串共享项目目录；会话 id 仍选择不同会话目录。在不区分大小写的文件系统上，只有文件系统规范化将两种写法解析到同一 transcript（文本记录）时，身份验证才接受备选路径写法。配置根仍由部署控制：可以是项目本地、共享、临时或集中式。[项目会话目录决策](../../../.agents/notes/implemented/architecture/2026-07-24-project-session-directories.md) 记录这项取舍。
 - 会话 id 是未验证的带品牌类型的字符串，因此在使用前单射转义为一个安全路径段（无遍历、无冲突）。结果目录保留给其他会话自有产物；发现只读取固定 transcript 文件名。

packages/session-persistence/session-persistence-jsonl/src/format.ts

@@ -37,6 +37,7 @@ export interface HeaderLine {
   cwd?: string
   parentSession?: SessionId
   seedLength?: number
+  origin?: 'subagent'
   delegationDepth: number
 }
 
@@ -54,6 +55,7 @@ export function toHeaderLine(header: SessionHeader): HeaderLine {
     ...header.cwd !== undefined ? { cwd: header.cwd } : {},
     ...header.parentSession !== undefined ? { parentSession: header.parentSession } : {},
     ...header.seedLength !== undefined ? { seedLength: header.seedLength } : {},
+    ...header.origin !== undefined ? { origin: header.origin } : {},
     delegationDepth: header.delegationDepth ?? 0,
   }
 }
@@ -74,6 +76,7 @@ export function fromHeaderLine(line: HeaderLine): SessionHeader {
     ...line.cwd !== undefined ? { cwd: line.cwd } : {},
     ...line.parentSession !== undefined ? { parentSession: line.parentSession } : {},
     ...line.seedLength !== undefined ? { seedLength: line.seedLength } : {},
+    ...line.origin !== undefined ? { origin: line.origin } : {},
     delegationDepth: line.delegationDepth,
   }
 }
@@ -93,6 +96,8 @@ function isHeaderLine(value: unknown): value is HeaderLine {
     && Number.isSafeInteger((value as { delegationDepth: number }).delegationDepth)
     && (value as { delegationDepth: number }).delegationDepth >= 0
     && !Object.is((value as { delegationDepth: number }).delegationDepth, -0)
+    && ((value as { origin?: unknown }).origin === undefined
+      || (value as { origin?: unknown }).origin === 'subagent')
   )
 }
 

packages/session-persistence/session-persistence-sqlite/src/index.ts

@@ -325,14 +325,15 @@ export class SessionPersistenceSqlite extends SessionPersistence implements Pers
   private writeRow(meta: SessionHeader): void {
     this.db.prepare(`
       INSERT INTO sessions
-        (id, version, created_at, cwd, parent_session, seed_length, delegation_depth, incarnation, revision)
-      VALUES (?, ?, ?, ?, ?, ?, ?, ?, 0)
+        (id, version, created_at, cwd, parent_session, seed_length, origin, delegation_depth, incarnation, revision)
+      VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, 0)
       ON CONFLICT(id) DO UPDATE SET
         version = excluded.version,
         created_at = excluded.created_at,
         cwd = excluded.cwd,
         parent_session = excluded.parent_session,
         seed_length = excluded.seed_length,
+        origin = excluded.origin,
         delegation_depth = excluded.delegation_depth
     `).run(
       meta.id,
@@ -341,6 +342,7 @@ export class SessionPersistenceSqlite extends SessionPersistence implements Pers
       meta.cwd ?? null,
       meta.parentSession ?? null,
       meta.seedLength ?? null,
+      meta.origin ?? null,
       meta.delegationDepth ?? null,
       randomUUID(),
     )

packages/session-persistence/session-persistence-sqlite/src/schema.ts

@@ -17,7 +17,7 @@ import type { SessionEvent, SessionId, SessionHeader, SurfaceOp } from '@deepsee
  * layout; orthogonal to a session's own `version` (which versions the EVENT
  * vocabulary, stored per session in the `sessions` row).
  */
-export const SCHEMA_VERSION = 12
+export const SCHEMA_VERSION = 13
 
 /** SQLite application id protecting unrelated databases from persistence writes. */
 export const SESSION_PERSISTENCE_SQLITE_APPLICATION_ID = 0x44534850
@@ -36,6 +36,7 @@ export interface SessionRow {
   cwd: string | null
   parent_session: string | null
   seed_length: number | null
+  origin: 'subagent' | null
   /** Stable identity assigned when this log is materialized. */
   incarnation: string
   /** Monotonic log-change token incremented in each mutating transaction. */
@@ -122,6 +123,7 @@ function configureDatabase(db: DatabaseSync, path: string, journalMode: JournalM
         cwd              TEXT,
         parent_session   TEXT,
         seed_length      INTEGER,
+        origin           TEXT,
         delegation_depth INTEGER,
         incarnation      TEXT NOT NULL,
         revision         INTEGER NOT NULL
@@ -180,6 +182,7 @@ export function rowToMeta(row: SessionRow): SessionHeader {
     ...row.cwd !== null ? { cwd: row.cwd } : {},
     ...row.parent_session !== null ? { parentSession: row.parent_session as SessionId } : {},
     ...row.seed_length !== null ? { seedLength: row.seed_length } : {},
+    ...row.origin !== null ? { origin: row.origin } : {},
     ...row.delegation_depth !== null ? { delegationDepth: row.delegation_depth } : {},
   }
 }

packages/session-persistence/session-persistence-sqlite/tests/sqlite.spec.ts

@@ -168,6 +168,7 @@ describe('rowToMeta', () => {
       cwd: null,
       parent_session: null,
       seed_length: null,
+      origin: null,
       incarnation: 'fractional',
       revision: 1,
       delegation_depth: null,
@@ -609,7 +610,7 @@ describe('SessionPersistenceSqlite: durability and crash semantics', () => {
   })
 
   it('exposes the schema version constant', () => {
-    expect(SCHEMA_VERSION).toBe(12)
+    expect(SCHEMA_VERSION).toBe(13)
   })
 
   it('keeps the revision stable for an empty repair hook', async () => {

packages/session-persistence/session-persistence/README.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write packages/session-persistence/session-persistence/README.md
-README.md: a8a4f14c8613a7e51bcf467e816b7f7bdb7ea80b
-README.zh.md: 369e8a01b8ac411ed9acfbac86b9b34db8037c1f
+README.md: 1acbef838aeb8ea1b1a0e4d08b12cd00b83d85ce
+README.zh.md: 74e6c62921bbcef431767a0274514e4c51f450d9

packages/session-persistence/session-persistence/README.md

@@ -4,7 +4,7 @@ English | [中文](README.zh.md)
 
 The abstract durable session-persistence seam (`ctx.sessionPersistence`). Defines WHAT a persistence backend does — durably store, reload, and list sessions — without saying HOW. Mirrors the `dsh-bash` capability-seam template ([capability seams](../../../.agents/notes/implemented/architecture/2026-06-13-capability-seams.md)): an abstract service here, a concrete implementation in a sibling package, consumers that inject the interface.
 
-The persisted unit IS the existing `SessionEvent` (event-sourced model — the log is the single source of truth), so there is no parallel "persisted message" type. Metadata that is NOT replayable conversation state (format version, cwd, lineage, seed boundary, delegation depth) travels separately as `SessionHeader`, owned by `dsh-session` and re-exported here.
+The persisted unit IS the existing `SessionEvent` (event-sourced model — the log is the single source of truth), so there is no parallel "persisted message" type. Metadata that is NOT replayable conversation state (format version, cwd, lineage, seed boundary, origin, delegation depth) travels separately as `SessionHeader`, owned by `dsh-session` and re-exported here.
 
 ## Service API (`ctx.sessionPersistence`)
 
@@ -62,7 +62,7 @@ Three backends run these suites: an in-memory reference (in `tests/`), `dsh-sess
 
 ## Metadata and location types
 
-Re-exported from `dsh-session`: `SessionHeader` (immutable session metadata: `version`, `id`, `createdAt`, `cwd?`, `parentSession?`, `seedLength?`, `delegationDepth?`). `SessionLocation` is `{ readonly kind: string; readonly path: string }`; its path is an absolute backend target, not proof that the artifact exists or contains an unflushed turn.
+Re-exported from `dsh-session`: `SessionHeader` (immutable session metadata: `version`, `id`, `createdAt`, `cwd?`, `parentSession?`, `seedLength?`, `origin?`, `delegationDepth?`). `SessionLocation` is `{ readonly kind: string; readonly path: string }`; its path is an absolute backend target, not proof that the artifact exists or contains an unflushed turn.
 
 ## Model Experience
 

packages/session-persistence/session-persistence/README.zh.md

@@ -4,7 +4,7 @@
 
 抽象的持久会话持久化 seam（`ctx.sessionPersistence`）。它定义持久化后端做什么：持久存储、重新加载和列出会话，而不规定如何实现。它与 `dsh-bash` 功能 seam 模板一致（见[功能 seam](../../../.agents/notes/implemented/architecture/2026-06-13-capability-seams.md)）：本包提供抽象服务，同级包提供具体实现，消费方注入接口。
 
-持久化单元就是现有 `SessionEvent`（事件溯源模型：日志是唯一真源），因此不存在并行的「持久消息」类型。不可回放的对话状态元数据（格式版本、cwd、血缘、种子边界、委托深度）作为 `SessionHeader` 单独传输，该类型归 `dsh-session` 所有，并在此重新导出。
+持久化单元就是现有 `SessionEvent`（事件溯源模型：日志是唯一真源），因此不存在并行的「持久消息」类型。不可回放的对话状态元数据（格式版本、cwd、血缘、种子边界、origin、委托深度）作为 `SessionHeader` 单独传输，该类型归 `dsh-session` 所有，并在此重新导出。
 
 ## 服务 API（`ctx.sessionPersistence`）
 
@@ -62,7 +62,7 @@
 
 ## 元数据与位置类型
 
-从 `dsh-session` 重新导出：`SessionHeader`（不可变会话元数据：`version`、`id`、`createdAt`、`cwd?`、`parentSession?`、`seedLength?`、`delegationDepth?`）。`SessionLocation` 是 `{ readonly kind: string; readonly path: string }`；其 path 是绝对后端目标，不证明产物已存在或包含未 flush 轮次。
+从 `dsh-session` 重新导出：`SessionHeader`（不可变会话元数据：`version`、`id`、`createdAt`、`cwd?`、`parentSession?`、`seedLength?`、`origin?`、`delegationDepth?`）。`SessionLocation` 是 `{ readonly kind: string; readonly path: string }`；其 path 是绝对后端目标，不证明产物已存在或包含未 flush 轮次。
 
 ## 模型体验
 

packages/session-persistence/session-persistence/tests/coordinator-contract.ts

@@ -276,7 +276,12 @@ export function runCoordinatorContract(name: string, makeFixture: () => Promise<
         let session!: Session
         const sessionFiber = await ctx.plugin(Object.assign((inner: Context) => {
           session = inner.sessions.create(SessionId('delegated-child'), {
-            meta: { cwd: WORK, parentSession: SessionId('root'), delegationDepth: 2 },
+            meta: {
+              cwd: WORK,
+              parentSession: SessionId('root'),
+              origin: 'subagent',
+              delegationDepth: 2,
+            },
           })
         }, { inject: ['sessions'] }))
         send(session, oneTurnLog())
@@ -285,6 +290,7 @@ export function runCoordinatorContract(name: string, makeFixture: () => Promise<
 
         const loaded = await ctx.sessionPersistence.load(SessionId('delegated-child'))
         expect(loaded.meta.delegationDepth).toBe(2)
+        expect(loaded.meta.origin).toBe('subagent')
       } finally {
         await fiber.dispose()
         await fix.cleanup()