docs(subagent): align settlement notice descriptions

docs/subsystems/subagent.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 docs/subsystems/subagent.md
-subagent.md: ae04dfd06cfda39a5bc8d7a079c9c3097c11193f
-subagent.zh.md: 730039af6a75e070b8b7f08021353a289927449e
+subagent.md: 21c75626158db666fd72bed2742b30e12f4cb719
+subagent.zh.md: ca4bb724b82f4f9e81f1e5b7653950ad8c2d3745

docs/subsystems/subagent.md

@@ -199,7 +199,7 @@ interface ContinuableStart {
 }
 ```
 
-When a resident Activation settles, the manager delivers one notice to the child's durable direct parent describing how that epoch ended and carrying its final assistant content. That delivery is unconditional for every child whose id a caller received, happens before the ownership release that would let the parent be judged settled, and reaches a resident parent through the same waking Agent delivery as an Agent message. A parent whose own lineage is already tearing down receives it without a wake, because waking an idle Agent starts a turn rather than queueing work. Its source has a distinct kind so a transcript never presents a runtime account as something the child wrote.
+When a resident Activation settles, the manager delivers one notice to the child's durable direct parent describing how that epoch ended and carrying the nonempty text blocks from its final assistant output, or `It left no closing message.` when none remain. That delivery is unconditional for every child whose id a caller received, happens before the ownership release that would let the parent be judged settled, and reaches a resident parent through the same waking Agent delivery as an Agent message. A parent whose own lineage is already tearing down receives it without a wake, because waking an idle Agent starts a turn rather than queueing work. Its source has a distinct kind so a transcript never presents a runtime account as something the child wrote.
 
 ```ts type-equiv
 /**

docs/subsystems/subagent.zh.md

@@ -199,7 +199,7 @@ interface ContinuableStart {
 }
 ```
 
-当驻留 Activation 结算时，管理器会向该 child 持久化的直接 parent 投递一条通知，说明该 epoch 如何结束，并携带其最终 assistant 内容。对每个调用方拿到过 id 的 child，这条投递都是无条件的；它发生在会让 parent 被判定为已结算的所有权释放之前，并通过与 Agent 消息相同的唤醒 Agent 投递到达驻留 parent。若 parent 自身所在的谱系已在拆卸中，这条通知会以不唤醒的方式送达，因为唤醒一个 idle Agent 是开启一个轮次，而不是排队等待工作。其来源信息使用一个独立的 kind，因此 transcript（文本记录）绝不会把运行时的记账呈现为 child 自己写下的内容。
+当驻留 Activation 结算时，管理器会向该 child 持久化的直接 parent 投递一条通知，说明该 epoch 如何结束，并携带其最终 assistant 输出中的非空文本块；若没有剩余的非空文本，则携带 `It left no closing message.`。对每个调用方拿到过 id 的 child，这条投递都是无条件的；它发生在会让 parent 被判定为已结算的所有权释放之前，并通过与 Agent 消息相同的唤醒 Agent 投递到达驻留 parent。若 parent 自身所在的谱系已在拆卸中，这条通知会以不唤醒的方式送达，因为唤醒一个 idle Agent 是开启一个轮次，而不是排队等待工作。其来源信息使用一个独立的 kind，因此 transcript（文本记录）绝不会把运行时的记账呈现为 child 自己写下的内容。
 
 ```ts type-equiv
 /**

packages/subagent/tool-subagent/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/subagent/tool-subagent/README.md
-README.md: f5ae099747ac1d6177df24ba90c61f17c3f7d05e
-README.zh.md: c9c962ad6773403e63c252e6ae321f02af476440
+README.md: f2d9eb3a44d84130caca8e29bbe0546e24a76b34
+README.zh.md: 312856983f0e25cd6eb8e508f4c7b9e9db361044

packages/subagent/tool-subagent/README.md

@@ -208,7 +208,7 @@ Append-only; newly visible content follows the reusable request prefix and does
 
 These limits define what this tool does not return or enforce; they are current package constraints.
 
-- **Background runs expose no result through this tool** — a one-shot task's final output is collected through the generic task surface, and a continuable child's output stays in its own session, read by its subagent id. The settlement notice states how that child ended and carries any final assistant message, but it is not this call's return value and cannot be awaited here.
+- **Background runs expose no result through this tool** — a one-shot task's final output is collected through the generic task surface, and a continuable child's output stays in its own session, read by its subagent id. The settlement notice states how that child ended and carries nonempty text from its final assistant output, but it is not this call's return value and cannot be awaited here.
 - **Duplicate names across waiting one-shot instances are detected late** (`TODO(subagent-dup-toolname)`) — continuable instances reserve their prompt-section name during plugin application, but preventing provider-registration rollback for waiting one-shot instances requires a registry of intended names.
 - **Shipped fork tools cannot select a child LLM route** — they inherit the parent's provider and model to keep the copied conversation prefix eligible for KV Cache reuse. Re-enable selection only when route changes preserve reuse or expose a bounded recomputation cost.
 - **Non-routing child policy is fixed per instance** — another persona, tool filter, or depth cap requires another distinctly named tool. LLM selection requires an enabled per-Session preference and a provider that advertises `agentOptions`; both in-process providers and DSH SDK advertise it, while ACP, Codex, and Claude Code reject it rather than ignore it.

packages/subagent/tool-subagent/README.zh.md

@@ -208,7 +208,7 @@ Use subagent in the background by default. Start independent delegations togethe
 
 这些限制说明本工具不返回或不强制执行什么；它们是当前包约束。
 
-- **后台运行不通过本工具公开结果**——一次性任务的最终输出通过通用 Task 接口收集，可继续子 agent 的输出留在其自身会话中，按其 subagent id 读取。结算通知会说明该子 agent 如何结束，并携带可能存在的最终 assistant 消息，但它不是本次调用的返回值，也无法在此等待。
+- **后台运行不通过本工具公开结果**——一次性任务的最终输出通过通用 Task 接口收集，可继续子 agent 的输出留在其自身会话中，按其 subagent id 读取。结算通知会说明该子 agent 如何结束，并携带其最终 assistant 输出中的非空文本，但它不是本次调用的返回值，也无法在此等待。
 - **等待中的一次性实例较晚才发现重复名称**（`TODO(subagent-dup-toolname)`）——可继续实例会在插件应用期间预留提示词 section 名称，但若要阻止等待中的一次性实例回滚提供方注册，仍需要一份预期名称注册表。
 - **随附 fork 工具不能选择子级 LLM 路由**——它们继承父级提供方与模型，使复制的对话前缀仍有资格复用 KV Cache。仅当路由变更能保留复用或公开有界重算成本时，才重新启用选择。
 - **非路由子 agent 策略按实例固定**——另一个 persona、工具过滤器或深度上限需要另一个名称不同的工具。LLM 选择要求启用逐 Session 偏好，且提供方必须声明 `agentOptions`；两个进程内提供方和 DSH SDK 会声明该能力，而 ACP、Codex 与 Claude Code 会拒绝它，而不是忽略它。