Merge remote-tracking branch 'origin/master' into xtr/agent-loop-message-machine

# Conflicts:
#	docs/architecture.i18n.yaml
#	docs/architecture.md
#	docs/architecture.zh.md
#	docs/cordis-catalog/services.md
#	docs/core-data-structures/core.i18n.yaml
#	docs/core-data-structures/core.md
#	docs/core-data-structures/core.zh.md
#	docs/core-data-structures/llm-streaming.i18n.yaml
#	docs/core-data-structures/session.i18n.yaml
#	docs/event-producer-consumer.md
#	examples/acp-agent/tests/snapshots/cordis-inspect-jsdoc/session.jsonl
#	examples/headless-agent/tests/snapshots/advanced-toolchain/session.1.jsonl
#	examples/headless-agent/tests/snapshots/advanced-toolchain/session.2.jsonl
#	packages/core/agent-loop/README.i18n.yaml
#	packages/core/agent-loop/README.md
#	packages/core/agent-loop/README.zh.md
#	packages/core/agent-loop/src/loop.ts
#	packages/core/agent/README.i18n.yaml
#	packages/core/agent/tests/llm-target.spec.ts
#	packages/core/session/tests/request-header.spec.ts

.agents/notes/implemented/simplification/2026-07-26-eventsource-parser-for-deepseek-sse.i18n.yaml

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+# Bilingual-pair consistency record (docs/i18n/README.md): the git blob hash of each
+# 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
+2026-07-26-eventsource-parser-for-deepseek-sse.md: e7835bc738b3dec5aefd6011848525f6604e852e
+2026-07-26-eventsource-parser-for-deepseek-sse.zh.md: 933b993d479026d8f2bd2dc3173abd9e60823806

.agents/notes/implemented/simplification/2026-07-26-eventsource-parser-for-deepseek-sse.md

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+# Agent Note: Replace the hand-rolled SSE parser in llm-deepseek with eventsource-parser
+
+Status: implemented
+
+English | [中文](2026-07-26-eventsource-parser-for-deepseek-sse.zh.md)
+
+## Problem
+
+`packages/llm/llm-deepseek/src/sse.ts` hand-implemented Server-Sent Events parsing: a streaming `TextDecoder`, event-block splitting on `\r?\n\r?\n`, `data:` payload extraction and joining, comment/field skipping, the `[DONE]` sentinel, a `STREAM_CLOSED` error on EOF without it, and a flush of a final unterminated event block. The file was ~67 lines with ~108 lines of dedicated tests (`tests/sse.spec.ts`) re-proving SSE spec behavior — UTF-8 split across chunks, CRLF handling, multi-`data:` joining, no-space-after-colon — that a maintained parser already guarantees. Its only consumer is `adapter.ts` (`yield* translate(parseSse(response.body))`).
+
+This is exactly the surface `eventsource-parser` owns: the de-facto standard SSE parser (it underlies the Vercel AI SDK and the MCP SDK), zero-dependency, actively maintained, and already present in this repo's lockfile transitively via `@modelcontextprotocol/sdk` — so adopting it directly adds no new supply-chain surface in practice.
+
+## Decision
+
+`sse.ts` delegates SSE framing to `EventSourceParserStream` from `eventsource-parser/stream`: `parseSse` pipes the response body through `new TextDecoderStream()` then `new EventSourceParserStream()` and keeps only the DeepSeek protocol shim — yield each event's `data`, terminate on `[DONE]`, and throw `LlmError('STREAM_CLOSED')` when the stream ends without the sentinel. All required builtins (`TextDecoderStream`, `pipeThrough`, async-iterable `ReadableStream`) exist at the Node ^22.19 engine floor. The spec-conformance tests are gone; `tests/sse.spec.ts` pins only the `[DONE]`/`STREAM_CLOSED`/EOF contract. `eventsource-parser` is `llm-deepseek`'s second runtime dependency after schemastery. The [twin-adapters note](../architecture/2026-06-13-twin-llm-adapters.md) and the `dsh-llm` JSDoc that branded this adapter "hand-rolled fetch + SSE parsing" now describe it as direct fetch with library-framed SSE.
+
+The library also strips a leading BOM (the hand-rolled parser would fail to match `data:` after one) and offers `maxBufferSize` hardening the hand-rolled parser lacked.
+
+## Alternatives considered
+
+- **Keep the hand-rolled parser.** Defensible under the [twin-adapters decision](../architecture/2026-06-13-twin-llm-adapters.md): the adapter is deliberately the hand-rolled design-verification twin of the pi-ai adapter. But that note's load-bearing distinction is owning the fetch/translate internals versus delegating to a full provider SDK; a ~700-byte SSE micro-parser is transport plumbing, not the design under verification. The twin-adapters note now states that reading explicitly.
+- **`createParser({onEvent})` callback API instead of the stream.** Works fed by a manual `TextDecoder` loop, but the `pipeThrough` composition deletes more of the hand-rolled code.
+
+## Consequences
+
+- The remaining shim only encodes the DeepSeek `[DONE]`/`STREAM_CLOSED` protocol; SSE framing edge cases are eventsource-parser's contract and are no longer re-proven here.
+- One deliberate robustness deviation is dropped: the hand-rolled parser flushed a final event block that lacked its terminating blank line, so a trailing `data: [DONE]` without `\n\n` still yielded DONE. eventsource-parser is spec-strict and only dispatches on the blank line, so that shape is now `STREAM_CLOSED`. Real providers and `dsh-llm-mock-server` always terminate events properly — the flush was a robustness nicety, not an observed provider shape — and `tests/sse.spec.ts` pins the new truncation verdict for that tail.
+- The documented "hand-rolled" identity of the twin adapter narrows to the fetch/translate internals; the twin-adapters note was updated in the same change rather than leaving the claim stale.

.agents/notes/implemented/simplification/2026-07-26-eventsource-parser-for-deepseek-sse.zh.md

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+# Agent Note: 用 eventsource-parser 替换 llm-deepseek 中手写的 SSE 解析器
+
+Status: implemented
+
+[English](2026-07-26-eventsource-parser-for-deepseek-sse.md) | 中文
+
+## 问题
+
+`packages/llm/llm-deepseek/src/sse.ts` 曾手写实现 SSE（Server-Sent Events）解析：一个流式 `TextDecoder`、按 `\r?\n\r?\n` 切分事件块、提取并拼接 `data:` 载荷、跳过注释与其他字段、`[DONE]` 哨兵、在未见哨兵即 EOF 时抛出 `STREAM_CLOSED` 错误，以及对最后一个未终结事件块的 flush。该文件约 67 行，另有约 108 行专属测试（`tests/sse.spec.ts`）重复验证 SSE 规范行为——UTF-8 字符被切分到多个分片、CRLF 处理、多条 `data:` 拼接、冒号后无空格——而这些行为，持续维护的解析器早已有保证。它唯一的消费方是 `adapter.ts`（`yield* translate(parseSse(response.body))`）。
+
+这恰好是 `eventsource-parser` 负责的接口面：事实标准的 SSE 解析器（Vercel AI SDK 和 MCP SDK 都构建在它之上），零依赖，持续维护，并且已通过 `@modelcontextprotocol/sdk` 作为传递依赖出现在本仓库的 lockfile 中——因此直接采用它实际上不增加新的供应链接触面。
+
+## 决策
+
+`sse.ts` 将 SSE 分帧委托给 `eventsource-parser/stream` 的 `EventSourceParserStream`：`parseSse` 把响应 body 依次管道接入 `new TextDecoderStream()` 和 `new EventSourceParserStream()`，只保留 DeepSeek 协议垫层——逐个产出事件的 `data`，遇到 `[DONE]` 终止，流在未见哨兵时结束则抛出 `LlmError('STREAM_CLOSED')`。所需的全部内置能力（`TextDecoderStream`、`pipeThrough`、可异步迭代的 `ReadableStream`）在 Node ^22.19 引擎下限即已存在。规范符合性测试已删除；`tests/sse.spec.ts` 只固定 `[DONE]`/`STREAM_CLOSED`/EOF 契约。`eventsource-parser` 是 `llm-deepseek` 继 schemastery 之后的第二个运行时依赖。曾把该适配器标为「手写 fetch + SSE 解析」的[孪生适配器 Agent Note（agent 决策记录）](../architecture/2026-06-13-twin-llm-adapters.md)与 `dsh-llm` JSDoc，现在将其描述为直接 fetch 加库分帧的 SSE。
+
+该库还会剥离开头的 BOM（手写解析器在 BOM 之后会无法匹配 `data:`），并提供手写解析器缺少的 `maxBufferSize` 加固能力。
+
+## 曾考虑的替代方案
+
+- **保留手写解析器。** 依据[孪生适配器决策](../architecture/2026-06-13-twin-llm-adapters.md)，这一选择有辩护余地：该适配器有意作为 pi-ai 适配器的手写设计验证孪生体。但那份 Agent Note 起支撑作用的区分在于「自行持有 fetch/translate 内部实现」与「委托给完整的提供方 SDK」；一个约 700 字节的 SSE 微型解析器属于传输层管道，不是被验证的设计本身。孪生适配器 Agent Note 现已明确写出这一解读。
+- **改用 `createParser({onEvent})` 回调 API 而非流。** 配合手动的 `TextDecoder` 循环可以工作，但 `pipeThrough` 组合方式能删除更多手写代码。
+
+## 后果
+
+- 剩下的垫层只编码 DeepSeek 的 `[DONE]`/`STREAM_CLOSED` 协议；SSE 分帧边界情形属于 eventsource-parser 的契约，不再在这里重复验证。
+- 放弃了一处有意为之的健壮性偏离：手写解析器会 flush 缺少终结空行的最后一个事件块，因此末尾的 `data: [DONE]` 即使没有 `\n\n` 也仍产出 DONE。eventsource-parser 严格遵循规范，只在空行处分发事件，所以这种形态现在是 `STREAM_CLOSED`。真实提供方和 `dsh-llm-mock-server` 总是正确终结事件——该 flush 只是健壮性上的锦上添花，并非实际观测到的提供方形态——`tests/sse.spec.ts` 固定了对该尾部的新截断判定。
+- 孪生适配器有文档记录的「手写」身份收窄到 fetch/translate 内部实现；孪生适配器 Agent Note 在同一次变更中更新，而不是让声明陈旧下去。