fix(client): address conversation assembly review

packages/client/runtime/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/client/runtime/README.md
-README.md: df3689176cf059f46004fa7ecb31ab7c326ea0bc
-README.zh.md: 9afe9773ff2a6a320bdf66978877678428c46118
+README.md: d4031c2e3b7730bdb0075ac84c50ad3e46ce63a2
+README.zh.md: ca6ac9f5e8efec3472c03b044739a9221e98183c

packages/client/runtime/README.md

@@ -58,7 +58,7 @@ Every `ToolCallBlock` recursively owns its children through `subCalls`, in start
 
 ## Model retry projection
 
-The Session object validates plugin-owned, provider-routed `llm/retry` payloads at the event wire boundary against the producer's complete field contract, including timer, integer, status, provider-delay, and non-empty diagnostic bounds. A valid event removes the matching failed step's streaming partial and inserts a durable retry notice at the event's sequence position. The notice is `scheduled` until a following retry turn starts; an aborted or disposed source turn marks it `cancelled`, while the retry turn marks it `started`. Normal-mode notices carry their finite maximum; always-mode notices remain explicitly unbounded. A terminal `turn/end` error without a retry projects one `turn-error` node from its durable message and optional code; AUTH projections replace provider copy that may echo credential fragments with `API key is invalid`, while the raw diagnostic remains in the session log. A retried failure keeps only the retry notice for that attempt. Window rebuild and history replay apply the same projection, so refresh neither resurrects discarded chunks nor loses terminal failure feedback. Visible unfinalized output is frozen as an interrupted assistant node beside the terminal error.
+The Host-owned LLM retry invariant validates provider-routed `llm/retry` and `llm/retry-started` records at the durable append boundary, including their identity, ordering, timer, integer, status, provider-delay, and non-empty diagnostic contracts. In the client, the Retry, Assistant, and Turn Error Definitions fold those records with Assistant and Turn/Step events: a failed step's streaming partial is removed and a durable retry notice appears at the retry event's sequence position. The notice is `scheduled` until the matching started record arrives; closing its owning Step or Turn first marks it `cancelled`, while the started record marks it `started`. Normal-mode notices carry their finite maximum; always-mode notices remain explicitly unbounded. A terminal `turn/end` error without a retry projects one `turn-error` node from its durable message and optional code; AUTH projections replace provider copy that may echo credential fragments with `API key is invalid`, while the raw diagnostic remains in the session log. A retried failure keeps only the retry notice for that attempt. Window rebuild and history replay use the same Definitions, so refresh neither resurrects discarded chunks nor loses terminal failure feedback. Visible unfinalized output is frozen as an interrupted Assistant node beside the terminal error.
 
 ## Session forking
 

packages/client/runtime/README.zh.md

@@ -58,7 +58,7 @@ Chat builder 为每个 Session 保留一个 mutable keyed store。内容更新
 
 ## 模型重试投影
 
-Session 对象会在事件 wire 边界依据生产方的完整字段约定，验证由插件负责、按提供方路由的 `llm/retry` 载荷，包括计时器、整数、状态、提供方延迟和非空诊断字段的边界。有效事件会移除对应失败步骤的流式输出片段，并在该事件的序列位置插入一条持久的重试提示。该提示在后续重试轮次开始前为 `scheduled`；源轮次中止或被 dispose 时，会将该提示标记为 `cancelled`，重试轮次则会将其标记为 `started`。normal mode 提示携带其有限上限；always mode 提示则保持显式无界。没有重试的终态 `turn/end` 错误会从持久消息与可选错误码投影出一个 `turn-error` 节点；AUTH 投影会把可能回显凭据片段的提供方文案替换为 `API key is invalid`，原始诊断仍保留在会话日志中。进入重试的失败则只保留该次尝试的重试提示。窗口重建与历史回放应用相同的投影，因此刷新既不会让已丢弃的分片重新出现，也不会丢失终态失败反馈。可见但尚未定稿的输出会在终态错误旁冻结为中断的 assistant 节点。
+Host 所属的 LLM retry invariant 会在持久追加边界验证按提供方路由的 `llm/retry` 与 `llm/retry-started` 记录，包括标识、顺序、计时器、整数、状态、提供方延迟和非空诊断字段约定。客户端的 Retry、Assistant 与 Turn Error Definition 把这些记录和 Assistant、Turn／Step 事件一起折叠：失败步骤的流式输出片段会被移除，并在 retry 事件的序列位置插入一条持久重试提示。该提示在匹配的 started 记录到达前为 `scheduled`；如果所属 Step 或 Turn 先关闭，则标记为 `cancelled`，started 记录到达后则标记为 `started`。normal mode 提示携带其有限上限；always mode 提示保持显式无界。没有重试的终态 `turn/end` 错误会从持久消息与可选错误码投影出一个 `turn-error` 节点；AUTH 投影会把可能回显凭据片段的提供方文案替换为 `API key is invalid`，原始诊断仍保留在会话日志中。进入重试的失败只保留该次尝试的重试提示。窗口重建与历史回放使用同一组 Definition，因此刷新既不会让已丢弃的分片重新出现，也不会丢失终态失败反馈。可见但尚未定稿的输出会在终态错误旁冻结为中断的 Assistant 节点。
 
 ## 会话 fork