feat(session): default JSONL writes to packed rows

docs/config-catalog.md

@@ -59,7 +59,7 @@ export interface Config {
   sessionTitle?: NonNullable<agentCore.Config['sessionTitle']>
   /** Directory for JSONL sessions and the derived query index. Defaults to `./.sessions`. */
   persistenceRoot?: string
-  /** Write delta-chunk runs as packed storage rows (the JSONL backend's `packChunks`). Defaults to `false`. */
+  /** Write delta-chunk runs as packed storage rows (the JSONL backend's `packChunks`). Defaults to `true`. */
   packChunks?: boolean
   /** JSONL artifact encoding; defaults to checksummed Zstandard frames. */
   persistenceCompression?: JsonlCompression
@@ -990,10 +990,9 @@ export interface Config {
   /**
    * Write runs of consecutive `assistant/chunk` delta events as packed
    * `text-chunks`/`reasoning-chunks`/`tool-call-chunks` rows (lossless,
-   * ~60% smaller logs measured on a real session). Off by default while
-   * snapshot fixtures stay in the one-event-per-line layout: recording with
-   * packing on rewrites every golden `session.jsonl`. READING packed rows is
-   * unconditional — a log's layout never depends on this switch.
+   * ~60% smaller logs measured on a real session). Defaults to true; false
+   * keeps one `SessionEvent` per line for diagnostics. Reading packed rows is
+   * unconditional: a log's layout never depends on this switch.
    */
   packChunks?: boolean
   /** Physical encoding; defaults to checksummed Zstandard frames. */

docs/core-data-structures/session.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
-session.md: d789ffcabb5cb0c744e265b61e322831c1d8a04f
-session.zh.md: f4f102861db7403520e9f38cb56613e430718cbe
+session.md: 2cbbac8042d04522fea0b1ed7a66c503e4b63f4e
+session.zh.md: e932c8f99f684f1b8985b006ab4ddb145db966bd

docs/core-data-structures/session.md

@@ -560,6 +560,6 @@ The hook bridges' `hook/invoked` / `hook/result` provenance pairs (from `@deepse
 
 ## Durability contract
 
-What a persistence backend relies on: the durable log persists every event losslessly, **including** `assistant/chunk` — `seq` must stay contiguous, so chunks cannot be filtered out of the canonical log. A backend may choose its own storage encoding for an event batch as long as `load` returns the exact appended events (the JSONL backend's opt-in packed chunk rows are such an encoding — see [persistence.md](persistence.md)). All `event.data` must be JSON-serializable; `Session.append` enforces this at the source (throwing on non-serializable data), so a bad event never enters the log and `session.events` always equals what a backend can persist. Adding an event type that carries non-serializable data, or that breaks the turn/step nesting checked by the session invariant companion, is a breaking change to the on-disk format.
+What a persistence backend relies on: the durable log persists every event losslessly, **including** `assistant/chunk` — `seq` must stay contiguous, so chunks cannot be filtered out of the canonical log. A backend may choose its own storage encoding for an event batch as long as `load` returns the exact appended events (the JSONL backend's default packed chunk rows are such an encoding — see [persistence.md](persistence.md)). All `event.data` must be JSON-serializable; `Session.append` enforces this at the source (throwing on non-serializable data), so a bad event never enters the log and `session.events` always equals what a backend can persist. Adding an event type that carries non-serializable data, or that breaks the turn/step nesting checked by the session invariant companion, is a breaking change to the on-disk format.
 
 The backends that consume this contract are on [persistence.md](persistence.md).

docs/core-data-structures/session.zh.md

@@ -564,6 +564,6 @@ interface TurnEndReasonMap {
 
 ## 持久性契约
 
-持久化后端依赖的契约如下：持久日志无损保存每个事件，**包括** `assistant/chunk`；`seq` 必须连续，因此不能从规范日志中过滤分片。后端可以为事件批次选择自己的存储编码，只要 `load` 返回与追加时完全一致的事件即可（JSONL 后端可选启用的打包分片行就是此类编码；见 [persistence.md](persistence.md)）。所有 `event.data` 都必须可序列化为 JSON；`Session.append` 会从源头强制这一要求（遇到不可序列化数据时抛出），因此错误事件绝不会进入日志，`session.events` 始终与后端可持久化的内容一致。新增携带不可序列化数据的事件类型，或破坏会话不变式配套插件所检查的轮次/步骤嵌套，会构成磁盘格式的破坏性变更。
+持久化后端依赖的契约如下：持久日志无损保存每个事件，**包括** `assistant/chunk`；`seq` 必须连续，因此不能从规范日志中过滤分片。后端可以为事件批次选择自己的存储编码，只要 `load` 返回与追加时完全一致的事件即可（JSONL 后端默认启用的打包分片行就是此类编码；见 [persistence.md](persistence.md)）。所有 `event.data` 都必须可序列化为 JSON；`Session.append` 会从源头强制这一要求（遇到不可序列化数据时抛出），因此错误事件绝不会进入日志，`session.events` 始终与后端可持久化的内容一致。新增携带不可序列化数据的事件类型，或破坏会话不变式配套插件所检查的轮次/步骤嵌套，会构成磁盘格式的破坏性变更。
 
 消费此契约的后端见 [persistence.md](persistence.md)。

docs/testing.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
-testing.md: 678d2e218590f70e6424a60286e46db87cf278cc
-testing.zh.md: 776f09bfe534f8460efda59623dc8f139cd43fe7
+testing.md: 3397c911aacf2db1050a5bcb5be53c0f63a4ddd0
+testing.zh.md: 5703acbf6a9962932d9842b2d39fbc799277fb92

docs/testing.md

@@ -12,6 +12,8 @@ How this repo tests, tier by tier, and the rules that keep a green suite meaning
 - **Snapshot** (`pnpm run test:snapshot`): keyless expected outputs cover external behavior — transport contracts and presentation, while persisted logs pin assembled backend behavior. ACP boots the real automation-server example, replays a recorded session, and diffs normalized JSON-RPC plus the re-persisted log ([ACP snapshot Agent Note](../.agents/notes/implemented/testing/2026-06-19-acp-snapshot-tests.md)); headless pins `stream-json` through its real one-shot process. TUI journeys replay primary/child JSONL through the real loop and tools, then project ANSI into semantic terminal-state outputs; package snapshots retain transient states and a real PTY covers the process boundary ([TUI snapshot Agent Note](../.agents/notes/implemented/testing/2026-07-18-tui-terminal-state-snapshots.md)). Use `pnpm run test:snapshot:record` when a model transcript changes and `pnpm run test:snapshot:refresh` when replay input remains valid; review every JSONL and expected-output diff. One ACP scenario (`text-turn`) pins full system-prompt/tool-schema content; other fixtures tokenize it so an edit churns one line ([pinned-header Agent Note](../.agents/notes/implemented/testing/2026-07-06-pin-request-header-content-in-one-scenario.md)).
 - **Web browser snapshot** (gate-exempt `pnpm run test:web`): real chromium over the in-process web composition replays recorded fixtures against conversation aria goldens (`apps/web/tests/snapshots/`); record/refresh semantics and the deferred CI browser decision: [web e2e lane Agent Note](../.agents/notes/implemented/testing/2026-07-24-web-gui-browser-e2e-lane.md).
 
+Committed session-format JSONL uses the canonical packed-row layout, and the keyless snapshot gate discovers every such fixture by its `session` header. In-flight branches carrying older fixture edits merge current `master` and run the [temporary migrator](../scripts/migrate-packed-session-fixtures.ts) through `pnpm run migrate:packed-session-fixtures`; the [removal proposal](../.agents/notes/proposed/process/2026-07-26-remove-packed-session-fixture-migrator.md) retires that command and these links after all affected branches converge.
+
 ## The with-key policy: inference is cheap here
 
 We are DeepSeek — do not ration real-API tests. A no-key test proves plumbing; only a with-key run proves the agent works against a real model. Cover file-writing prompts, multi-turn conversations, tool use, and mid-stream cancellation. Highest-value are **smoke tests** that boot the real example, send one prompt, and check the world — they catch the "green unit tests, broken product" class that mocks cannot ([postmortem 0001](postmortem/0001-acp-default-export-drops-inject.md)). Self-skip keeps secretless CI and keyless contributors unblocked; it is not a cost signal. Every example ships keyless and with-key smokes ([examples/AGENTS.md](../examples/AGENTS.md)).

docs/testing.zh.md

@@ -12,6 +12,8 @@
 - **快照**（`pnpm run test:snapshot`）：无密钥预期输出覆盖对外行为（传输契约与呈现），持久化日志则固定组装后的后端行为。ACP 启动真实的自动化服务器示例、回放录制会话，并对归一化 JSON-RPC 与重新持久化的日志执行 diff（[ACP 快照 Agent Note](../.agents/notes/implemented/testing/2026-06-19-acp-snapshot-tests.md)）；headless 通过真实单次运行进程固定 `stream-json`。TUI 旅程通过真实循环与工具回放主会话与子会话 JSONL，再将 ANSI 投影为语义化终端状态输出；包级快照保留瞬态状态，真实 PTY 覆盖进程边界（[TUI 快照 Agent Note](../.agents/notes/implemented/testing/2026-07-18-tui-terminal-state-snapshots.md)）。当模型 transcript（文本记录）发生变化时使用 `pnpm run test:snapshot:record`，回放输入仍然有效时使用 `pnpm run test:snapshot:refresh`；请审查每一处 JSONL 与预期输出差异。一个 ACP 场景（`text-turn`）固定完整的系统提示词与工具 schema 内容；其他 fixture（测试前置数据）将其 token 化，因此修改只会扰动一行（[pinned-header Agent Note](../.agents/notes/implemented/testing/2026-07-06-pin-request-header-content-in-one-scenario.md)）。
 - **Web 浏览器快照**（豁免门禁的 `pnpm run test:web`）：真实 chromium 在进程内 web 组装之上回放已录制 fixture，与会话区 aria 预期输出比对（`apps/web/tests/snapshots/`）；`DSH_SNAPSHOT=record`/`refresh` 的语义与暂缓的 CI 浏览器决策见 [web e2e 车道 Agent Note](../.agents/notes/implemented/testing/2026-07-24-web-gui-browser-e2e-lane.md)。
 
+签入仓库的会话格式 JSONL 使用规范打包行布局，无密钥快照门禁会通过 `session` header 发现每一份此类 fixture。仍携带旧版 fixture 改动的在途分支应合并当前 `master`，并通过 `pnpm run migrate:packed-session-fixtures` 运行[临时迁移器](../scripts/migrate-packed-session-fixtures.ts)；待所有受影响分支收敛后，[移除提案](../.agents/notes/proposed/process/2026-07-26-remove-packed-session-fixture-migrator.md)会移除该命令及这些链接。
+
 ## 带密钥策略：推理在这里很便宜
 
 我们是 DeepSeek，不要吝惜真实 API 测试。无密钥测试只能证明底层通路；只有带密钥运行才能证明 agent（智能体）能对接真实模型正常工作。覆盖文件写入提示词、包含多个轮次的对话、工具使用和流中取消。价值最高的是**冒烟测试**：启动真实示例、发送一条提示词，并检查外部世界；它们能捕获「单元测试全绿、产品却坏了」这一类 mock 无法发现的问题（[事故复盘 0001](postmortem/0001-acp-default-export-drops-inject.md)）。自动跳过让无密钥 CI 和无密钥贡献者不受阻塞；它不是成本信号。每个示例都提供无密钥和带密钥冒烟测试（[examples/AGENTS.md](../examples/AGENTS.md)）。