fix(agent-loop): second review pass — late-steering discard, dead-branch, catalog leaks

Address a second fresh-eye review of the review fixes:
- MAJOR: late steering that lands after runTurn returns terminally
  stopped (e.g. during the post-turn flush) was drained by runLoop and
  dropped without a discard, leaving a dangling outstanding id the
  negative-only invariant can't catch. Emit agent/inbox/discard for it,
  symmetric with the in-turn terminal-stop drop.
- remove the dead cancel() idle-settle branch: whenIdle's fast path
  already resolves for a lone quiet item, so no waiter is ever left for
  it to settle. Document why.
- gen-cordis-api classShape now drops private/protected/#private members
  and strips getter/setter bodies, so Session no longer leaks private
  fields and getter bodies into the model catalog.
- document that AgentMessage intentionally omits meta (durable-only).

Adds a regression test for the late-steering discard.

.agents/notes/implemented/architecture/2026-07-22-unified-send-and-coalesced-user-messages.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
-2026-07-22-unified-send-and-coalesced-user-messages.md: e969012c8172bbba78f04943be46b7dc866ccb7f
-2026-07-22-unified-send-and-coalesced-user-messages.zh.md: 35cc183a7c7bfd8a649557e50e6e7d379f8f8193
+2026-07-22-unified-send-and-coalesced-user-messages.md: 9eb355128b217a0ea8dc09daf4e83334f6aeaa10
+2026-07-22-unified-send-and-coalesced-user-messages.zh.md: 679c9100aa49777b7b601725bdfc077f5f2dab0e

.agents/notes/implemented/architecture/2026-07-22-unified-send-and-coalesced-user-messages.md

@@ -36,7 +36,7 @@ Separately, `context/message` and `user/message` had converged: the surface proj
 
 The delivery surface is now one primitive plus three self-documenting presets, and the (`target` × `wakeup`) matrix makes previously-unreachable combinations explicit. One durable message type serves prompts, injected context, and goal rounds, so the surface projection and every "human prompt?" check simplify to a `source` test. The cost: `Agent` became an abstract class, so object-literal test fakes must supply `followup` and cannot spread a class-typed value without re-casting (prototype methods are non-enumerable); the goal fold's channel split moved from event type to `source.round`; and every consumer that filtered `context/message` now filters `user/message` by source. The turn-enclosure and reconstruction invariants are unchanged — an idle injection still wraps a one-shot turn, now emitting `user/message` instead of `context/message`.
 
-`wakeup` is the "should the model run" signal, so the inbox distinguishes `hasWakingQueued` (drives the loop and idle/quiescence decisions) from `hasQueued` (anything to dequeue): a lone `next-turn`/no-wakeup item stays parked at idle and rides along the next waking send, and `whenIdle`/`cancel` settle quiescence off the waking signal. `SendOptions.meta` on a queued or steering send is carried onto the durable `user/message`/`steering/message`, matching injection. Every FIFO exit publishes exactly one lifecycle event: a terminal `agent/turn-stop` that drops pending steering now emits `agent/inbox/discard` for it, and a loop-authored continuation reason is snapshotted and frozen like a public send. `gen-cordis-api` collects exported classes (body-stripped) so the now-class `Agent` and its transitive shapes still appear in the model-facing API catalog.
+`wakeup` is the "should the model run" signal, so the inbox distinguishes `hasWakingQueued` (drives the loop and idle/quiescence decisions) from `hasQueued` (anything to dequeue): a lone `next-turn`/no-wakeup item stays parked at idle and rides along the next waking send, and `whenIdle`/`cancel` settle quiescence off the waking signal (a lone quiet item takes `whenIdle`'s fast path, so no waiter is ever left hanging). `SendOptions.meta` on a queued or steering send is carried onto the durable `user/message`/`steering/message`, matching injection; it is intentionally not on the live `AgentMessage` event, which carries only routing facts. Every FIFO exit publishes exactly one lifecycle event: a terminal stop that drops pending steering emits `agent/inbox/discard` for it — both at the in-turn stop point and on the post-turn drain of late steering — and a loop-authored continuation reason is snapshotted and frozen like a public send. `gen-cordis-api` collects exported classes (public members, body-stripped) so the now-class `Agent` and its transitive shapes still appear in the model-facing API catalog.
 
 ## Related
 

.agents/notes/implemented/architecture/2026-07-22-unified-send-and-coalesced-user-messages.zh.md

@@ -36,7 +36,7 @@ agent 的对外驱动接口逐渐长出三个近乎平行的动词——`send`
 
 投递接口现在是一个原语加三个自解释的预设，(`target` × `wakeup`) 矩阵把此前无法表达的组合显式化。一种持久消息类型同时服务提示词、注入的上下文和 goal 轮次，因此对外接口的投影和每一处“是否人类提示词？”检查都简化为一次 `source` 判断。代价是：`Agent` 变成了抽象类，因此对象字面量形式的测试替身必须提供 `followup`，且无法在不重新做类型转换的情况下展开一个类类型的值（原型方法不可枚举）；goal 折叠的通道区分从事件类型改到了 `source.round`；此前过滤 `context/message` 的每个消费方现在改为按来源过滤 `user/message`。轮次封闭与重建的不变量保持不变——空闲状态下的一次注入仍然封装成一个一次性轮次，只是现在发出 `user/message` 而非 `context/message`。
 
-`wakeup` 是“模型是否应当运行”的信号，因此 inbox 区分 `hasWakingQueued`（驱动 loop 以及空闲/静默判定）与 `hasQueued`（是否有任何可 dequeue 的项）：一个孤立的 `next-turn`/no-wakeup 队列项会停泊在空闲状态，并随下一次唤醒 send 一同带出，而 `whenIdle`/`cancel` 依据唤醒信号来结算静默。排队 send 或 steering send 上的 `SendOptions.meta` 会被带到持久的 `user/message`/`steering/message` 上，与注入保持一致。每一次 FIFO 退出都恰好发布一个生命周期事件：一次会丢弃待处理 steering 项的终止性 `agent/turn-stop` 现在会为它发出 `agent/inbox/discard`，而由 loop 生成的继续原因会像一次对外 send 那样被快照并冻结。`gen-cordis-api` 收集导出的类（剥除方法体），因此如今已是类的 `Agent` 及其传递涉及的形状仍会出现在面向模型的 API 目录中。
+`wakeup` 是“模型是否应当运行”的信号，因此 inbox 区分 `hasWakingQueued`（驱动 loop 以及空闲/静默判定）与 `hasQueued`（是否有任何可 dequeue 的项）：一个孤立的 `next-turn`/no-wakeup 队列项会停泊在空闲状态，并随下一次唤醒 send 一同带出，而 `whenIdle`/`cancel` 依据唤醒信号来结算静默（一个孤立的静默项走 `whenIdle` 的快速路径，因此不会有等待者被永久挂起）。排队 send 或 steering send 上的 `SendOptions.meta` 会被带到持久的 `user/message`/`steering/message` 上，与注入保持一致；它有意不放在实时的 `AgentMessage` 事件上，后者只携带路由事实。每一次 FIFO 退出都恰好发布一个生命周期事件：一次会丢弃待处理 steering 项的终止性停止会为它发出 `agent/inbox/discard`——既在轮次内的停止点，也在轮次结束后对迟到 steering 的清空时——而由 loop 生成的继续原因会像一次对外 send 那样被快照并冻结。`gen-cordis-api` 收集导出的类（公开成员，剥除方法体），因此如今已是类的 `Agent` 及其传递涉及的形状仍会出现在面向模型的 API 目录中。
 
 ## 相关