fix(agent-loop): park empty turn batches, keep max-tokens sticky, and settle headless at idle

- turn boundary now returns false for an empty admitted batch (claimed
  input removed before the wake) instead of opening a turn and spending a
  model call on nothing; the step boundary already had the symmetric guard.
- a max-token step stays sticky when steering or injected work continues
  the turn: a later completed step no longer downgrades the outcome,
  matching the TurnEndReasonMap contract.
- session/queue wire schema accepts the context placement (previously the
  zod union rejected injected-context snapshots wholesale and the client
  silently dropped the whole frame); schema tests cover all placements.
- headless runs settle at whole-agent idle instead of the first turn/end,
  honoring the one-shot idle-to-idle contract.
- flush JSDoc names the real callers (checkpoint policy, goal-session,
  teardown, self-flushing consumers); apiproxy zh README loses its stale
  duplicate history section; ACP note/README record the delivered error
  rejection and turnless-cancelled behaviors.

.agents/notes/implemented/architecture/2026-07-30-followup-enqueue-and-owned-runs.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 .agents/notes/implemented/architecture/2026-07-30-followup-enqueue-and-owned-runs.md
-2026-07-30-followup-enqueue-and-owned-runs.md: 12da1d770c9346e79394c194f33e7faae2254cdf
-2026-07-30-followup-enqueue-and-owned-runs.zh.md: c7b839d1207151002a0cff1a470245198561b2d8
+2026-07-30-followup-enqueue-and-owned-runs.md: 54f4af75eeb29b06504fa2629b0665f3e5f4c4ee
+2026-07-30-followup-enqueue-and-owned-runs.zh.md: 62c0d998a8bf94df8cabfccf23ea8b2a4da92c4d

.agents/notes/implemented/architecture/2026-07-30-followup-enqueue-and-owned-runs.md

@@ -18,7 +18,7 @@ The low-level SDK protocol answers `session/prompt` as soon as enqueue succeeds
 
 High-level automation APIs return a `RunResult` only when they explicitly own an activity interval. The TypeScript and Python SDK `run()` methods collect from the submitted message's durable inbox receipt through the next whole-agent `idle`; their `finalResponse` is the last committed assistant message in that interval, not a response causally attributed to the submitted prompt. The one-shot CLI owns the analogous idle-to-idle interval. An isolated child-agent run may report a result because its caller owns the complete child lifecycle and any steering belongs to that run.
 
-ACP must return a protocol `stopReason`. Its bridge serializes one in-flight prompt per ACP session, waits for whole-agent idle, reports `cancelled` only for explicit ACP cancellation or disposal, and otherwise reports the generic `end_turn`. It does not infer token-limit or error attribution for the prompt.
+ACP must return a protocol `stopReason`. Its bridge serializes one in-flight prompt per ACP session, waits for whole-agent idle, and otherwise reports the generic `end_turn`. Token-limit endings are not attributed to the prompt: they settle as `end_turn`. A model error on the prompt's correlated turn does reject the prompt immediately (the error is attributed by its owning turn), and a turnless slot (admission discarded the prompt) settles as `cancelled` at idle alongside explicit ACP cancellation or disposal.
 
 Goal continuation retains `MessageId` only to recognize its durable queued and admitted goal message. It advances from durable goal state at whole-agent idle, without mapping the message to a turn result.
 

.agents/notes/implemented/architecture/2026-07-30-followup-enqueue-and-owned-runs.zh.md

@@ -18,7 +18,7 @@ Status: implemented
 
 只有明确拥有一个活动区间时，高层自动化 API 才返回 `RunResult`。TypeScript 和 Python SDK 的 `run()` 方法从已提交消息的持久 inbox 回执开始收集，直至整个 agent 下一次进入 `idle`；其 `finalResponse` 是该区间内最后一条已提交的 assistant 消息，而不是按因果关系归属于已提交提示词的响应。单次 CLI（命令行界面）拥有相应的 idle 到 idle 区间。隔离的子 agent 运行可以报告结果，因为调用方拥有完整的子级生命周期，任何 steering 都属于该运行。
 
-ACP（Agent Client Protocol）必须返回协议规定的 `stopReason`。其桥接层串行处理每个 ACP 会话中唯一一个正在处理的提示词，等待整个 agent 进入 idle，仅在显式 ACP 取消或资源释放时报告 `cancelled`，其他情况均报告通用的 `end_turn`。它不推断 token 上限或错误是否归属于该提示词。
+ACP（Agent Client Protocol）必须返回协议规定的 `stopReason`。其桥接层串行处理每个 ACP 会话中唯一一个正在处理的提示词，等待整个 agent 进入 idle，其他情况均报告通用的 `end_turn`。token 上限的轮次结束不归因于提示词：它们以 `end_turn` 结算。与该提示词关联的轮次上的模型错误会立即以该错误 reject 提示词（错误按其所属轮次归因），而 turnless 槽位（准入已丢弃提示词）会在 idle 时以 `cancelled` 结算，与显式 ACP 取消或资源释放并列。
 
 Goal 续行只保留 `MessageId`，用于识别持久排队和已准入的 goal 消息。它在整个 agent 进入 idle 时根据持久 goal 状态推进，不把消息映射到轮次结果。