Steer a queued Web message into the active turn
将 Web 已排队消息转为活动轮次的 steering（中途引导）
The Web composer originally queued every Enter submission while an agent ran. QueueDock already gives each pending message an addressable row, and the durable transcript already renders consumed steer events as user-style bubbles, but Web had neither an action connecting those two surfaces nor a direct composer gesture for choosing current-turn steering. Implementing the row action as a client-side delete followed by
English
Problem
The Web composer originally queued every Enter submission while an agent ran. QueueDock already gives each pending message an addressable row, and the durable transcript already renders consumed steer events as user-style bubbles, but Web had neither an action connecting those two surfaces nor a direct composer gesture for choosing current-turn steering.
Implementing the row action as a client-side delete followed by session.prompt(mode: 'steer') would split one user intent across two RPCs. Driver claim could win between them, the steer could fail after deletion, or the existing best-effort agent.steer() fallback could silently append a new Queue item after the original occurrence was removed. A send-now action must therefore distinguish current-turn steering from Queue promotion and preserve the original row when steering is no longer possible.
Decision
Product contract
Each non-editing ordinary-session QueueDock row exposes the upward-arrow action as “插话发送”. The action is enabled only while the session reports a running agent; mixed-content messages remain eligible because steering forwards the complete immutable UserMessage rather than the row's text projection. An addressed subagent keeps its Queue projection read-only because its continuation transport does not expose queue mutation.
Activating the action requests strict current-turn steering for that exact InboxItemId. Success removes the Queue row through the authoritative Host snapshot and immediately projects the same pending steering after the Deep diving... running-status row; that bubble offers Copy but no Fork because the message has no durable event sequence yet. Once AgentLoop drains it, the existing durable user/message event takes over the same user-style bubble and restores its clock, Copy, and Fork without a separate durable presentation path.
The running bit is only an interaction hint. AgentLoop's acceptsNextStep value is authoritative at the synchronous mutation boundary. If that window has closed, the operation leaves the Queue occurrence unchanged and returns a typed steer-unavailable error, after which the original waking occurrence proceeds through Queue. If the driver already claimed the occurrence, it returns the existing queue-item-not-found error and independent-turn delivery is already underway. The UI treats both races as converged Queue delivery without a failure notice; transport and unknown errors still surface.
The composer uses a separate best-effort contract for newly typed input. While the addressed session is idle, Enter and Cmd/Ctrl+Enter both perform an ordinary Queue send. While a primary session is running, a General Settings preference assigns plain Enter to Queue (the default) or Steer, and Cmd/Ctrl+Enter performs the other behavior; Shift+Enter inserts a newline. An addressed subagent keeps both gestures on its Queue-only continuation transport. The Host settings document persists the preference across Web origins sharing one DSH home, and it affects only the steer-capable busy-state gesture pair. If a direct composer Steer misses the current next-step window, AgentLoop automatically admits it as the next waking Queue turn and the Web does not report a failure.
Agent and lifecycle boundary
InboxAction gains a consumer-backed { kind: 'steer' } operation alongside edit and remove. Agent.updateInbox() handles it only after locating the queued occurrence and proving acceptsNextStep; it never delegates to the best-effort agent.steer() alias.
An applied action ends the queued occurrence and accepts the same immutable UserMessage as a new steering occurrence. The steering occurrence receives a new InboxItemId and truthful placement: 'steering', while the message retains its MessageId, content, source, and any pending SteeringReceipt delivery controller. AgentLoop installs the new outbox entry before publishing lifecycle events, then emits its enqueue before the old occurrence's discard so re-entrant cancellation cannot observe or retire an unannounced item. The existing inbox conservation invariant therefore continues to require one enqueue and one terminal dequeue or discard for each occurrence.
The action does not run agent/prompt-submit: choosing steering intentionally changes delivery from an independently admitted turn to current-turn next-step input. It neither cancels current work nor reorders the remaining Queue.
Host and client boundary
session.updateQueue carries the steer action and maps the two negative outcomes to typed RPC errors. The conversion is one synchronous Agent operation; the Host never reconstructs it by combining remove and prompt calls.
The Host's existing queuedMirror remains the sole transient inbox authority. Its session/queue snapshot carries every live occurrence with placement: 'queued' | 'steering': QueueDock renders only queued rows, while ChatView renders pending steering at the conversation tail after the Deep diving... running-status row, with Copy but without Fork, edit, or delete actions. Reconnect replays the same snapshot, so this visibility does not require client optimism or a second registry.
When AgentLoop claims pending steering, it emits agent/inbox/dequeue immediately before synchronously appending the durable user/message. The Host retires that steering row on the following microtask, allowing the durable session event to enter the linear mux stream first. On the accepted live event, the client Session retires the first matching current steering occurrence before publishing its snapshot; history replay does not consume a later occurrence that reused the same MessageId. ChatView therefore renders one authority at a time without scanning durable history, and the durable projection restores the clock, Copy, and Fork against its logged event time and sequence. An append failure still retires the claimed row.
The existing session.prompt(mode: 'steer') contract remains best-effort for new primary-session input: outside the next-step window it becomes a waking follow-up. The composer carries an explicit queue | steer mode through slash adjudication and reference serialization before calling that contract. A browser submission policy owns the live busy-Enter preference while the Host settings service owns durability; the policy resolves plain versus accelerated Enter as complementary gestures only for steer-capable sessions, and the Settings row and InputBar share it without duplicating storage or delivery-window authority. Only the Queue row action is strict, because either negative result converges through the original Queue occurrence.
Verification
AgentLoop contract coverage holds prompt admission open, converts one exact queued occurrence, and proves the replacement steering occurrence keeps the message value and delivery receipt, drains as a user/message, and never starts its former independent turn. It also pins unavailable-window retention, claimed-address rejection, and re-entrant cancellation lifecycle conservation.
Host schema and proxy tests cover the new action, both typed errors, placement-aware snapshots and reconnect replay, plus durable-before-retirement ordering. Client tests cover silent convergence of both semantic races, genuine error reporting, read-only subagent rows and Queue-only subagent gestures. Runtime and ChatView tests cover occurrence-aware pending-to-durable handoff, including repeated MessageId values, while Web ARIA snapshots cover pending steering after the running-status row with Copy alone and the durable node with clock, Copy, and Fork.
The keyless Web steering scenario queues a message through the real composer while the first response streams, activates the row arrow, then uses ask_user_question as a stable pending-steering barrier. It proves the Host-backed pending bubble appears before admission, hands off to one durable interjection after the answer, and affects the next model request. Assembled composer scenarios prove default-mode Cmd+Enter reaches the same pending and durable path without creating a Queue row, while Steer-mode Cmd+Enter creates a Queue row instead. Settings and submission-policy coverage pin the default, persistence, busy-only scope, and complementary gesture mapping; Queue edit/delete scenarios continue to prove those actions are unchanged.
Alternatives considered
Delete the row, then call session.prompt(mode: 'steer') from Web. Rejected because two RPCs cannot make deletion and steering atomic; failure and driver-claim races can lose or duplicate the user's message.
Restore Queue promotion under the upward arrow. Rejected because moving an item to the front still creates an independent admitted turn. The control promises current-turn steering, not priority within Queue.
Use the existing best-effort agent.steer() behavior for the Queue row. Rejected for that action because a closed next-step window would create a new queued occurrence, possibly at a different position and identity. Strict refusal preserves the original occurrence so the UI can treat it as the same accepted Queue delivery. Newly typed composer input has no existing Queue occurrence to preserve, so it intentionally uses the best-effort behavior.
Change agent.steer() to be strict for every caller. Rejected because TUI and plugin callers use its safe follow-up fallback for newly submitted input. A queued row has recoverable state that those callers do not.
Preserve the same InboxItemId while changing placement. Rejected because InboxItemId identifies one FIFO acceptance and placement records that acceptance's resolved delivery. Ending one queued occurrence and accepting one steering occurrence keeps lifecycle facts truthful and leaves the conservation invariant unchanged.
Add a dedicated pending-steering projection and client store. Rejected because queued and steering occurrences already share one Agent inbox lifecycle and one Host mirror. A second projection would duplicate reconnect state and ordering authority; a placement tag lets each client surface select its rows without widening Queue mutation semantics.
Cancel the active turn and run the selected Queue item. Rejected because it destroys unrelated in-flight work and starts a new turn rather than steering the current one.
Consequences
session/queue describes a placement-aware transient inbox snapshot rather than a Queue-only list, so every consumer must filter by placement. Pending steering survives reconnect and appears immediately, but remains non-durable until the durable user/message commits. The running bit can also remain true briefly after the strict next-step window closes, so an enabled action may internally return steer-unavailable while the product continues through Queue without reporting failure.
The explicit action changes delivery from an independently admitted turn to current-turn steering, so prompt-admission plugins do not process the converted message. Enqueue-before-discard lifecycle publication remains required for re-entrant cancellation safety; focused regression coverage protects that ordering.
中文
问题
Web composer 原本会在 agent（智能体）运行期间把所有 Enter 提交作为 Queue 入队。QueueDock 已经为每条待处理消息提供可寻址的行，持久 transcript（文本记录）也已能把消费后的 steer 事件渲染为用户样式气泡，但 Web 既没有连接这两个界面的操作，也没有让用户从 composer 直接选择当前轮次 steering 的手势。
如果 Web 先在客户端删除该行，再调用 session.prompt(mode: 'steer')，就会把用户的一次意图拆分到两个 RPC 中。驱动器可能在两次调用之间先认领该项，steering 投递也可能在删除后失败；现有尽力而为的 agent.steer() 回退还可能在原单次入队项被移除后，静默追加一个新的 Queue 项。因此，立即发送操作必须区分当前轮次 steering 与 Queue 前移，并在 steering 已不可用时保留原行。
决策
产品约定
普通会话中每个非编辑态的 QueueDock 行都会提供名为「插话发送」的向上箭头操作。仅当会话报告 agent 正在运行时，该操作才会启用；包含混合内容的消息仍可使用，因为 steering 会转发完整且不可变的 UserMessage，而非该行的文本投影。已寻址 subagent 的 Queue 投影保持只读，因为其继续执行传输不提供 Queue 变更。
触发该操作会针对对应的 InboxItemId 请求严格的当前轮次 steering。操作成功后，权威 Host 快照会移除 Queue 行，并在 Deep diving... 运行状态行之后立即投影同一条待处理 steering；该气泡提供复制，但消息尚无持久事件序号，因此不提供 fork。AgentLoop 排空该项后，现有持久 user/message 事件会接管同一个用户样式气泡，并恢复时钟、复制和 fork，无需另建持久展示路径。
running 标志位只用于提示交互状态。在同步变更边界上，AgentLoop 的 acceptsNextStep 值才是权威依据。如果该窗口已经关闭，操作会保持 Queue 单次入队项不变并返回类型化的 steer-unavailable 错误，随后原唤醒单次入队项会经 Queue 继续执行。如果驱动器已经认领该项，则返回现有的 queue-item-not-found 错误，且独立轮次投递已经开始。UI 会把两种竞态都视为已收敛的 Queue 投递，不显示失败通知；传输和未知错误仍会显示。
Composer 对新输入采用另一套尽力而为约定。所寻址会话空闲时，Enter 和 Cmd/Ctrl+Enter 都执行普通 Queue 发送。主会话运行期间，General Settings 偏好会把普通 Enter 分配为 Queue（默认值）或 Steer，Cmd/Ctrl+Enter 则执行另一种行为；Shift+Enter 用于换行。已寻址 subagent 会让这两个手势都使用其仅支持 Queue 的继续执行传输。Host settings 文档会在共享同一 DSH home 的 Web origin 之间持久化该偏好，并且它只影响支持 steering 的繁忙态手势对。如果 composer 直接发出的 Steer 错过当前 next-step 窗口，AgentLoop 会自动将其接纳为下一条唤醒 Queue 轮次，Web 不显示失败。
Agent 与生命周期边界
InboxAction 会在编辑和移除之外，新增由实际消费方支撑的 { kind: 'steer' } 操作。Agent.updateInbox() 只有在找到 queued 单次入队项并确认 acceptsNextStep 后才会处理该操作，绝不会委托给尽力而为的 agent.steer() 别名。
操作成功应用后，系统会结束 queued 单次入队项，并把同一个不可变 UserMessage 接受为新的 steering 单次入队项。steering 单次入队项会获得新的 InboxItemId 和如实反映投递方式的 placement: 'steering'，消息则保留其 MessageId、内容、来源和任何待处理 SteeringReceipt 投递控制器。AgentLoop 会先安装新的 outbox 项，再发布生命周期事件；随后先发出新单次入队项的 enqueue，再发出旧单次入队项的 discard，确保可重入取消无法观察或退役一个尚未公布的项。因此，现有 inbox 守恒不变量仍然要求每个单次入队项恰好对应一个 enqueue，以及一个终态 dequeue 或 discard。
该操作不会运行 agent/prompt-submit：选择 steering 会有意把投递方式从经独立接纳的轮次改为当前轮次的 next-step 输入。它既不会取消当前工作，也不会重新排序 Queue 中的剩余项。
Host 与客户端边界
session.updateQueue 会携带 steer 操作，并把两种负面结果映射为类型化 RPC 错误。这项转换是一次同步 Agent 操作；Host 绝不会通过组合移除和提示词调用来重建它。
Host 仍以现有 queuedMirror 作为唯一的瞬态 inbox 权威。session/queue 快照会携带所有存活单次入队项及其 placement: 'queued' | 'steering'：QueueDock 只渲染 queued 行，ChatView 则在会话流末尾、Deep diving... 运行状态行之后渲染待处理 steering，提供复制操作，但不提供 fork、编辑或删除操作。重连会重放同一份快照，因此这项可见性既不依赖客户端乐观展示，也不需要第二个注册表。
AgentLoop 认领待处理 steering 时，会在同步追加持久 user/message 之前立即发出 agent/inbox/dequeue。Host 会等到下一个微任务才退役该 steering 行，让持久会话事件先进入线性 mux 流。客户端 Session 接纳该实时事件时，会在发布快照前退役第一个匹配的当前 steering 单次入队项；历史回放不会消费后来复用同一 MessageId 的单次入队项。因此，ChatView 无需扫描持久历史就能每次只渲染一份权威，持久投影则会根据已记录的事件时间与序号恢复时钟、复制与 fork 操作。追加失败时，已认领行仍会退役。
现有 session.prompt(mode: 'steer') 对主会话新输入仍采用尽力而为的约定：在 next-step 窗口之外，它会变为唤醒 agent 的后续轮次。Composer 会让显式 queue | steer 模式经过 slash 裁决与引用序列化，再调用该约定。浏览器提交策略拥有实时繁忙态 Enter 偏好，而 Host settings 服务拥有持久性；该策略只为支持 steering 的会话把普通 Enter 与加速 Enter 解析为互补手势，Settings 行和 InputBar 共享该策略，不重复实现存储或投递窗口权威。只有 Queue 行操作采用严格语义，因为任一种负面结果都会经原 Queue 单次入队项收敛。
验证
AgentLoop 约定覆盖保持提示词接纳窗口打开，转换一个精确的 queued 单次入队项，并证明替代它的 steering 单次入队项保留消息值和投递回执、以 user/message 的形式排空，且绝不启动原本的独立轮次。该覆盖还钉住窗口不可用时保留原项、拒绝已被认领的地址，以及可重入取消下的生命周期守恒。
Host schema 和代理测试覆盖新操作、两种类型化错误、带 placement 的快照与重连重放，以及先持久化再退役的顺序。客户端测试覆盖两种语义竞态的静默收敛、真实错误报告、只读 subagent 行和仅支持 Queue 的 subagent 手势。运行时与 ChatView 测试覆盖按单次入队项完成的待处理到持久交接，包括重复的 MessageId 值；Web ARIA 快照则覆盖位于运行状态行之后且仅有复制的待处理 steering，以及带时钟、复制和 fork 的持久节点。
无密钥 Web steering 场景在第一次响应流式输出期间，通过真实 composer 排队一条消息并触发行上的箭头，再用 ask_user_question 作为稳定的待处理 steering 屏障。该场景证明 Host 支撑的待处理气泡会在准入前出现，在回答后交接为唯一一条持久插话，并影响下一次模型请求。组装后的 composer 场景证明默认模式下的 Cmd+Enter 无需创建 Queue 行，也会进入同一条待处理与持久路径；Steer 模式下的 Cmd+Enter 则会创建 Queue 行。Settings 与提交策略覆盖会固定默认值、持久化、仅限繁忙态的作用域和互补手势映射；Queue 编辑／删除场景继续证明这些操作没有变化。
考虑过的替代方案
在 Web 中删除该行，再调用 session.prompt(mode: 'steer')。 不予采纳，因为两个 RPC 无法让删除和 steering 成为原子操作；失败和驱动器认领竞态可能丢失或重复用户消息。
恢复向上箭头对应的 Queue 前移操作。 不予采纳，因为把某个项移到队首仍然会创建一个独立接纳的轮次。该控件承诺的是当前轮次 steering，而不是 Queue 内的优先级。
为 Queue 行使用现有尽力而为的 agent.steer() 行为。 不予采纳，因为关闭的 next-step 窗口会创建新的 queued 单次入队项，而且位置和标识可能不同。严格拒绝会保留原单次入队项，让 UI 能将其视为同一次已接纳的 Queue 投递。新输入的 composer 消息没有需要保留的现有 Queue 单次入队项，因此有意采用尽力而为行为。
让每个调用方使用的 agent.steer() 都采用严格语义。 不予采纳，因为 TUI 和插件调用方会针对新提交的输入使用其安全的后续轮次回退。queued 行具有这些调用方不具备的可恢复状态。
改变投递方式时保留同一个 InboxItemId。 不予采纳，因为 InboxItemId 标识一次 FIFO 接受，而 placement 记录该次接受解析出的投递方式。结束一个 queued 单次入队项并接受一个 steering 单次入队项，能够使生命周期事实保持如实，并让守恒不变量保持不变。
增加专用的待处理 steering 投影和客户端 store。 不予采纳，因为 queued 与 steering 单次入队项已经共享同一套 Agent inbox 生命周期和 Host mirror。第二份投影会重复保存重连状态与顺序权威；placement 标签能让各客户端界面选取自己的行，而不扩大 Queue 变更语义。
取消活动轮次并运行选中的 Queue 项。 不予采纳，因为这会破坏无关的进行中工作，并且会启动新轮次，而不是 steering 当前轮次。
后果
session/queue 表示带 placement 的瞬态 inbox 快照，而不只是 Queue 列表，因此每个消费方都必须按 placement 过滤。待处理 steering 会在界面中立即出现并能在重连后恢复，但在持久 user/message 提交前仍不持久。严格 next-step 窗口关闭后，running 标志位仍可能短暂保持为 true，因此已启用的操作可能会在内部返回 steer-unavailable，而产品仍经 Queue 继续执行且不显示失败。
这项显式操作会把投递方式从经独立接纳的轮次改为当前轮次 steering，因此提示词接纳插件不会处理转换后的消息。为保证可重入取消安全，生命周期事件仍必须先发布 enqueue 再发布 discard；有针对性的回归覆盖会保护这一顺序。