fix(agent-loop): scope blocked admission cleanup

packages/core/agent/README.md

@@ -52,7 +52,7 @@ The lifecycle edges have two important local caveats. `agent/created` runs after
 
 Most interception points are cooperative waterfalls. Turn-scoped asynchronous seams receive one explicit `AbortSignal`, with `signal` immediately before a waterfall's final `next`; listeners may cooperate but must not retain it as authority over another turn. `agent/step` is the serial checkpoint before request derivation, while `agent/request-error` is the failed-model-request recovery waterfall: it receives request coordinates, normalized failure facts, the serving registration's retry policy when available, and the signal. A listener returns `{ kind: 'retry' }` without calling `next()` when it owns recovery. `agent/turn-stopping` runs before an otherwise completed turn closes. Ordinary queued prompts remain intact. The [explicit-cancellation decision](../../../.agents/notes/implemented/architecture/2026-07-16-explicit-turn-cancellation.md) owns signal lifetime; the [agent-scope runtime-design Agent Note](../../../.agents/notes/implemented/architecture/2026-07-12-agent-scope-runtime-design.md#three-execution-boundaries-are-deliberately-one-way) owns scoped dispatch and terminal settlement.
 
-`PromptDecision.allow.messages` is the complete identified, frozen batch admitted by prompt interception. A listener that wraps a downstream allow preserves that batch unless it intentionally replaces it.
+`PromptDecision.allow.messages` is the complete identified, frozen batch admitted by prompt interception. A listener that wraps a downstream allow preserves that batch unless it intentionally replaces it. A block must choose `discardClaimed`; this affects only the submitted batch, while messages not claimed by that admission remain pending.
 
 Turn and step boundaries and the model token stream are durable `session/event` facts rather than mirrored `agent/*` notifications. Consumers read `turn/*`, `step/*`, and `assistant/chunk` from the session feed; tool policy and outcome observation belong to the complete pipeline documented by [`dsh-tools`](../tools/README.md).
 

packages/core/agent/README.zh.md

@@ -52,7 +52,7 @@ Agent *创建* 由实现 `AgentFactory` 的插件（`dsh-agent-loop`）提供，
 
 大多数拦截点都是协作式 waterfall（瀑布式事件）。轮次作用域的异步 seam 接收一个显式 `AbortSignal`，其中 `signal` 紧邻 waterfall 最终的 `next`；监听器可以配合，但不得将它保留为控制另一轮次的权限。`agent/step` 是派生请求前的串行检查点，而 `agent/request-error` 是失败模型请求的恢复 waterfall：它接收请求坐标、规范化失败事实、可用时提供服务的注册项重试策略以及信号。拥有恢复权的监听器返回 `{ kind: 'retry' }` 且不调用 `next()`。`agent/turn-stopping` 在本可完成的轮次关闭前运行。普通排队提示词保持原样。信号生命周期由[显式取消决策](../../../.agents/notes/implemented/architecture/2026-07-16-explicit-turn-cancellation.md)拥有；作用域分发与终止结算由 [agent 作用域 runtime 设计 Agent Note（agent 决策记录）](../../../.agents/notes/implemented/architecture/2026-07-12-agent-scope-runtime-design.md#three-execution-boundaries-are-deliberately-one-way)拥有。
 
-`PromptDecision.allow.messages` 是提示词拦截所准入的完整、带标识且冻结的批次。包装下游 allow 的监听器会保留该批次，除非有意替换它。
+`PromptDecision.allow.messages` 是提示词拦截所准入的完整、带标识且冻结的批次。包装下游 allow 的监听器会保留该批次，除非有意替换它。block 必须指定 `discardClaimed`；该字段仅影响本次提交的批次，未被此次接纳认领的消息会继续保持待处理。
 
 轮次和步骤边界以及模型 token 流是持久 `session/event` 事实，而不是镜像的 `agent/*` 通知。消费方从会话事件流读取 `turn/*`、`step/*` 和 `assistant/chunk`；工具策略与结果观测属于 [`dsh-tools`](../tools/README.md) 记录的完整流水线。
 

packages/core/agent/src/types.ts

@@ -50,12 +50,13 @@ export type AgentStatus = 'idle' | 'running'
 
 /**
  * Prompt interception result. An allowed batch replaces the submitted
- * messages. A listener wrapping `next()` preserves the returned batch unless
- * it intentionally replaces it.
+ * messages; a listener wrapping `next()` preserves that batch unless it
+ * intentionally replaces it. A blocked batch explicitly chooses whether to
+ * discard the claimed messages; unclaimed work remains pending.
  */
 export type PromptDecision =
   | { kind: 'allow'; messages: UserMessage[] }
-  | { kind: 'block'; reason: string; keepInbox?: boolean }
+  | { kind: 'block'; reason: string; discardClaimed: boolean }
 
 /** One failed model-request attempt presented to recovery listeners. */
 export interface RequestFailureContext {