Merge latest master into PR 555

# Conflicts:
#	.agents/notes/implemented/architecture/2026-07-25-web-input-machine-and-slash-pipeline.i18n.yaml
#	.agents/notes/implemented/architecture/2026-07-25-web-input-machine-and-slash-pipeline.md
#	.agents/notes/implemented/architecture/2026-07-25-web-input-machine-and-slash-pipeline.zh.md
#	packages/client/ui-conversation/README.i18n.yaml
#	packages/client/ui-conversation/src/client/chat/MessageItem.tsx
#	packages/client/ui-conversation/src/client/input/facade.ts
#	packages/client/ui-conversation/src/client/input/hub.ts
#	packages/client/ui-conversation/src/client/service.ts
#	packages/client/ui-conversation/tests/apply-inject.spec.tsx
#	packages/client/ui-conversation/tests/input-bar.spec.tsx
#	packages/client/ui-conversation/tests/input-matrix.spec.tsx
#	packages/client/ui-conversation/tests/input-scenarios.spec.tsx
#	packages/client/ui-conversation/tests/skeleton.spec.tsx

packages/client/ui-conversation/src/client/chat/MessageItem.module.css

@@ -29,16 +29,6 @@
   color: var(--dsw-alias-label-primary);
 }
 
-.badge {
-  display: inline-block;
-  margin-bottom: 4px;
-  padding: 1px 6px;
-  border-radius: 6px;
-  background: var(--dsw-alias-state-warn-primary);
-  color: var(--dsw-alias-label-primary-foreground);
-  font-size: 11px;
-}
-
 .contextRow {
   padding: 2px 0;
 }

packages/client/ui-conversation/src/client/chat/MessageItem.tsx

@@ -1,6 +1,7 @@
 // MessageItem: simple chat nodes — user bubble (right-aligned, with
-// clock + copy / branch IconActions), steering (badged bubble), context
-// injection, compaction marker, retry disclosure, and unknown-surface JSON rows.
+// clock + copy / branch IconActions), steering (same bubble, no actions),
+// context injection, compaction marker, retry disclosure, and
+// unknown-surface JSON rows.
 
 import { memo, useEffect, useMemo, useState } from 'react'
 import type { ReactNode } from 'react'
@@ -178,25 +179,31 @@ function projectUserText(text: string): ReactNode {
   return <>{parts}</>
 }
 
-function UserContentStack({ parts, imageLoader, steering = false, t, truncated }: {
-  parts: ReturnType<typeof contentParts>
+/** Right-aligned bubble shared by user and steering rows (steering has no actions). */
+function UserStyleBubble({
+  content, imageLoader, actions, t,
+}: {
+  content: readonly unknown[]
   imageLoader: ImageLoader
-  steering?: boolean
+  /** Optional IconActions (or similar) below the bubble; receives the joined text. */
+  actions?: (text: string) => ReactNode
   t: ChatViewSlotProps['t']
-  truncated: (total: number) => string
-}) {
-  const { text, images, rest } = parts
-  const showBubble = steering || text !== '' || rest.length > 0
+}): ReactNode {
+  const { text, images, rest } = contentParts(content)
+  const truncated = (total: number): string => t('json.truncated', { total })
+  const showBubble = text !== '' || rest.length > 0
   return (
-    <div className={css.userStack}>
-      <ImageGallery images={images} load={imageLoader} align="end" t={t} />
-      {showBubble && <div className={css.bubble}>
-        {steering && <span className={css.badge}>{t('message.steering')}</span>}
-        {projectUserText(text)}
-        {rest.map((block, i) => (
-          <JsonBlock key={i} label={t('message.extraBlock')} payload={block} truncatedLabel={truncated} />
-        ))}
-      </div>}
+    <div className={css.userRow}>
+      <div className={css.userStack}>
+        <ImageGallery images={images} load={imageLoader} align="end" t={t} />
+        {showBubble && <div className={css.bubble}>
+          {projectUserText(text)}
+          {rest.map((block, i) => (
+            <JsonBlock key={i} label={t('message.extraBlock')} payload={block} truncatedLabel={truncated} />
+          ))}
+        </div>}
+      </div>
+      {actions?.(text)}
     </div>
   )
 }
@@ -207,30 +214,26 @@ export const MessageItem = memo(function MessageItem({
   const imageLoader = loadImage ?? (() => Promise.reject(new Error(t('image.serviceUnavailable'))))
   const truncated = (total: number): string => t('json.truncated', { total })
   switch (node.kind) {
-    case 'user': {
-      const parts = contentParts(node.content)
+    case 'user':
       return (
-        <div className={css.userRow}>
-          <UserContentStack parts={parts} imageLoader={imageLoader} t={t} truncated={truncated} />
-          <MessageIconActions
-            text={parts.text}
-            time={node.time}
-            clock="start"
-            onBranch={onFork === undefined ? undefined : () => { onFork(node.seq) }}
-            className={css.actions}
-            t={t}
-          />
-        </div>
+        <UserStyleBubble
+          content={node.content}
+          imageLoader={imageLoader}
+          t={t}
+          actions={text => (
+            <MessageIconActions
+              text={text}
+              time={node.time}
+              clock="start"
+              onBranch={onFork === undefined ? undefined : () => { onFork(node.seq) }}
+              className={css.actions}
+              t={t}
+            />
+          )}
+        />
       )
-    }
-    case 'steering': {
-      const parts = contentParts(node.content)
-      return (
-        <div className={css.userRow}>
-          <UserContentStack parts={parts} imageLoader={imageLoader} steering t={t} truncated={truncated} />
-        </div>
-      )
-    }
+    case 'steering':
+      return <UserStyleBubble content={node.content} imageLoader={imageLoader} t={t} />
     case 'context':
       return (
         <ContextInjectionRow content={node.content} source={node.source} t={t} />

packages/client/ui-conversation/src/client/input/contract.ts

@@ -43,7 +43,7 @@ export interface SessionInput extends InputTarget {
   /** Drop ids whose browser objects no longer exist. */
   pruneImages(ids: readonly DraftAttachmentId[]): void
   /** THE complexity sink: enter adjudication, submit transaction, and the default sink live inside. */
-  submit(mode?: 'queue' | 'steer'): void
+  submit(): void
   /**
    * Surface a notice outside the machine's own effect stream: detached
    * command results and business notifications render through here.
@@ -83,7 +83,7 @@ export interface InputActions {
   /** Drop ids whose browser objects no longer exist. */
   pruneImages(ids: readonly DraftAttachmentId[]): void
   /** Enter submission (adjudication / claim transaction / default sink inside). */
-  submit(mode?: 'queue' | 'steer'): void
+  submit(): void
 }
 
 /** One surfaced notice (command results, adjudication failures). seq keys re-render of repeats. */
@@ -264,7 +264,7 @@ export type InputEvent =
   | { readonly type: 'paste-upgrade'; readonly attemptId: number; readonly span: TokenSpan; readonly reference: ReferenceInsert }
   /** Shell-observed attempt killers the machine cannot see itself (caret/selection ops, Slash interaction updates). */
   | { readonly type: 'invalidate-paste' }
-  | { readonly type: 'enter'; readonly mode: 'queue' | 'steer' }
+  | { readonly type: 'enter' }
   | { readonly type: 'adjudicated'; readonly attempt: SubmitAttempt; readonly outcome: PickOutcome }
   | { readonly type: 'adjudication-failed'; readonly attempt: SubmitAttempt; readonly message: string }
   | { readonly type: 'submit-settled'; readonly attempt: SubmitAttempt; readonly ok: boolean; readonly outcome?: SubmitOutcome; readonly message?: string }
@@ -283,5 +283,5 @@ export type InputEvent =
 export type InputEffect =
   | { readonly type: 'adjudicate'; readonly attempt: SubmitAttempt; readonly draft: string }
   | { readonly type: 'begin-submit'; readonly attempt: SubmitAttempt; readonly claim: CommandClaim; readonly args: string }
-  | { readonly type: 'default-sink'; readonly draft: string; readonly mode: 'queue' | 'steer' }
+  | { readonly type: 'default-sink'; readonly draft: string }
   | { readonly type: 'notice'; readonly level: 'info' | 'error'; readonly text: string }

packages/client/ui-conversation/src/client/input/facade.ts

@@ -39,7 +39,7 @@ export interface SessionInputDeps {
   /** Queue read face; overlaid onto InputState.queue (absent = empty). */
   queue?: ObservableSnapshot<readonly QueuedMessage[]> | undefined
   /** The plain-message sink (send choreography / materialize fork — the hub owns it). */
-  defaultSink(text: string, mode: 'queue' | 'steer', imageIds: readonly DraftAttachmentId[]): void
+  defaultSink(text: string, imageIds: readonly DraftAttachmentId[]): void
 }
 
 /** Guard tier from the machine phase. */
@@ -71,7 +71,7 @@ export class SessionInputShell implements SessionInput {
     addImages: ids => this.addImages(ids),
     removeImage: (id) => { this.removeImage(id) },
     pruneImages: (ids) => { this.pruneImages(ids) },
-    submit: (mode) => { this.submit(mode) },
+    submit: () => { this.submit() },
   }
 
   // Real wall clock: the typing-run merge window must actually expire in
@@ -200,14 +200,13 @@ export class SessionInputShell implements SessionInput {
    * from the machine; this method only feeds the event. Lock entry
    * (adjudicating/submitting) force-closes the transient layers: the popup
    * dismisses and the menu tracks frozen.
-   * @param mode - default-sink mode (queue appends; steer interrupts).
    */
-  submit(mode: 'queue' | 'steer' = 'queue'): void {
+  submit(): void {
     if (this.snapshot.draft.trim() === '' && this.imageIds.length > 0) {
-      if (this.snapshot.phase === 'plain') this.deps.defaultSink('', mode, [...this.imageIds])
+      if (this.snapshot.phase === 'plain') this.deps.defaultSink('', [...this.imageIds])
       return
     }
-    this.run(this.core.dispatch({ type: 'enter', mode }))
+    this.run(this.core.dispatch({ type: 'enter' }))
     const phase = this.snapshot.phase
     if (phase === 'adjudicating' || phase === 'submitting') {
       this.deps.popup?.()?.dismiss()
@@ -392,7 +391,7 @@ export class SessionInputShell implements SessionInput {
         return
       }
       case 'default-sink': {
-        this.sinkSerialized(fx.draft, fx.mode)
+        this.sinkSerialized(fx.draft)
         return
       }
       default:
@@ -407,11 +406,11 @@ export class SessionInputShell implements SessionInput {
    * send — notice + draft and chips retained, never a silent downgrade to
    * the clipboard text. Chip-free drafts skip the async detour.
    */
-  private sinkSerialized(draft: string, mode: 'queue' | 'steer'): void {
+  private sinkSerialized(draft: string): void {
     const imageIds = [...this.imageIds]
     const occurrences = this.core.state.occurrences
     if (occurrences.length === 0) {
-      this.deps.defaultSink(draft.trim(), mode, imageIds)
+      this.deps.defaultSink(draft.trim(), imageIds)
       return
     }
     const slash = this.deps.slash?.()
@@ -431,7 +430,7 @@ export class SessionInputShell implements SessionInput {
           cursor = part.offset + 1
         }
         out += draft.slice(cursor)
-        this.deps.defaultSink(out.trim(), mode, imageIds)
+        this.deps.defaultSink(out.trim(), imageIds)
       },
       (error: unknown) => {
         controller.abort()

packages/client/ui-conversation/src/client/input/hub.ts

@@ -25,7 +25,6 @@ interface ConversationAttachmentFace {
   sendSession(
     session: SessionFace,
     text: string,
-    mode: 'queue' | 'steer',
     imageIds: readonly DraftAttachmentId[],
   ): Promise<void>
   releaseDraftImage(id: DraftAttachmentId): void
@@ -67,7 +66,7 @@ export class InputHub implements InputService {
       slash: () => this.controller(actx),
       popup: () => this.popup(actx),
       queue: queueReadFaceOf(session),
-      defaultSink: (text, mode, imageIds) => { this.sink(session, text, mode, imageIds) },
+      defaultSink: (text, imageIds) => { this.sink(session, text, imageIds) },
     })
     this.shells.set(id, shell)
     // The one teardown axis: listeners, shell, and map entries all ride the
@@ -148,14 +147,13 @@ export class InputHub implements InputService {
   private sink(
     session: SessionFace,
     text: string,
-    mode: 'queue' | 'steer',
     imageIds: readonly DraftAttachmentId[],
   ): void {
     if (text === '' && imageIds.length === 0) return
     const shell = this.shells.get(session.sessionId)
     // Commit, not an editable clear: undo must not resurrect sent content.
     shell?.commitSend(imageIds)
-    void this.conversation().sendSession(session, text, mode, imageIds).catch(() => {
+    void this.conversation().sendSession(session, text, imageIds).catch(() => {
       // Restore only into the shell that still owns the session: if the scope
       // died while the send was in flight, `commitSend` already removed the
       // ids from the (now disposed) shell, so the teardown release could not

packages/client/ui-conversation/src/client/input/machine.ts

@@ -112,7 +112,6 @@ export class InputMachine {
   private inflight: {
     readonly attempt: SubmitAttempt
     readonly controller: AbortController
-    readonly mode: 'queue' | 'steer'
   } | undefined
   private log: Transaction[] = []
   private redoStack: Transaction[] = []
@@ -164,7 +163,7 @@ export class InputMachine {
         this.paste = undefined
         return []
       }
-      case 'enter': return this.onEnter(ev.mode)
+      case 'enter': return this.onEnter()
       case 'adjudicated': return this.onAdjudicated(ev.attempt, ev.outcome)
       case 'adjudication-failed': return this.onAdjudicationFailed(ev.attempt, ev.message)
       case 'submit-settled': return this.onSubmitSettled(ev)
@@ -463,18 +462,18 @@ export class InputMachine {
   // ---- submit plane ----
 
   /** Mint the next SubmitAttempt and take the in-flight slot. */
-  private beginAttempt(mode: 'queue' | 'steer'): SubmitAttempt {
+  private beginAttempt(): SubmitAttempt {
     const controller = new AbortController()
     this.seq += 1
     const attempt: SubmitAttempt = { seq: this.seq, signal: controller.signal, draftSnapshot: this.draft }
-    this.inflight = { attempt, controller, mode }
+    this.inflight = { attempt, controller }
     return attempt
   }
 
-  private onEnter(mode: 'queue' | 'steer'): InputEffect[] {
+  private onEnter(): InputEffect[] {
     if (this.phase === 'adjudicating' || this.phase === 'submitting') return []
     if (this.phase === 'claimed' && this.claim !== undefined) {
-      const attempt = this.beginAttempt(mode)
+      const attempt = this.beginAttempt()
       this.phase = 'submitting'
       this.paste = undefined
       return [{ type: 'begin-submit', attempt, claim: this.claim, args: argsAfter(this.draft, this.claim.token) }]
@@ -483,11 +482,11 @@ export class InputMachine {
     if (trimmed === '') return []
     this.paste = undefined
     if (trimmed.startsWith('/')) {
-      const attempt = this.beginAttempt(mode)
+      const attempt = this.beginAttempt()
       this.phase = 'adjudicating'
       return [{ type: 'adjudicate', attempt, draft: this.draft }]
     }
-    return [{ type: 'default-sink', draft: this.draft, mode }]
+    return [{ type: 'default-sink', draft: this.draft }]
   }
 
   private onAdjudicated(attempt: SubmitAttempt, outcome: Extract<InputEvent, { type: 'adjudicated' }>['outcome']): InputEffect[] {
@@ -508,7 +507,7 @@ export class InputMachine {
     this.inflight = undefined
     this.phase = 'plain'
     return outcome === undefined
-      ? [{ type: 'default-sink', draft: attempt.draftSnapshot, mode: flight.mode }]
+      ? [{ type: 'default-sink', draft: attempt.draftSnapshot }]
       : []
   }
 

packages/client/ui-conversation/src/client/locales.ts

@@ -61,7 +61,6 @@ export const zh = {
   'chat.loadOlder': '加载更早',
   'chat.toBottom': '回到底部',
   'message.extraBlock': '附加内容块',
-  'message.steering': '插话',
   'message.contextInjection': '上下文注入',
   'message.compaction': '上下文已压缩',
   'message.compaction.expand': '点击查看压缩摘要',
@@ -176,7 +175,6 @@ export const en = {
   'chat.loadOlder': 'Load earlier',
   'chat.toBottom': 'Back to bottom',
   'message.extraBlock': 'Extra content block',
-  'message.steering': 'Interjection',
   'message.contextInjection': 'Context injection',
   'message.compaction': 'Context compacted',
   'message.compaction.expand': 'View compaction summary',

packages/client/ui-conversation/src/client/service.ts

@@ -27,12 +27,11 @@ export interface IConversation {
   /** The per-session input machine registry (InputService face). */
   readonly input: InputService
   /**
-   * Send a prompt into the caller scope's session.
+   * Send a prompt into the caller scope's session (queued turn).
    * @param text - prompt text, sent verbatim as one text block.
-   * @param mode - queue after the current turn, or steer into it.
    * @returns completion; business failures reject (and land in promptError).
    */
-  send(text: string, mode: 'queue' | 'steer'): Promise<void>
+  send(text: string): Promise<void>
   /**
    * Apply one operation to a pending queue occurrence.
    * @param itemId - agent-owned inbox occurrence identity.
@@ -110,11 +109,10 @@ export class ConversationService extends Service implements IConversation {
    * session snapshot's promptError (object-layer surface); the rejection here
    * exists for caller choreography (the composer restores the draft on it).
    * @param text - prompt text, sent verbatim as one text block when non-empty.
-   * @param mode - queue after the current turn, or steer into it.
    */
-  async send(text: string, mode: 'queue' | 'steer'): Promise<void> {
+  async send(text: string): Promise<void> {
     const session = this.scopedSession('send')
-    await this.sendFiles(session, text, mode, [])
+    await this.sendFiles(session, text, [])
   }
 
   /**
@@ -123,32 +121,29 @@ export class ConversationService extends Service implements IConversation {
    * persisted or stale id.
    * @param session - target session.
    * @param text - serialized prompt text.
-   * @param mode - queue or steer.
    * @param imageIds - ordered draft-local attachment ids.
    */
   async sendSession(
     session: SessionFace,
     text: string,
-    mode: 'queue' | 'steer',
     imageIds: readonly DraftAttachmentId[],
   ): Promise<void> {
     const attachments = this.draftImages(imageIds)
     if (attachments.length !== imageIds.length) {
       throw new Error('conversation.sendSession: one or more draft images are no longer available')
     }
-    await this.sendFiles(session, text, mode, attachments.map(attachment => attachment.file))
+    await this.sendFiles(session, text, attachments.map(attachment => attachment.file))
     this.releaseDraftImages(attachments)
   }
 
   private async sendFiles(
     session: SessionFace,
     text: string,
-    mode: 'queue' | 'steer',
     images: readonly File[],
   ): Promise<void> {
     const uploaded = await this.serializeImages(images)
     const content = [...uploaded, ...(text === '' ? [] : [{ type: 'text' as const, text }])]
-    const result = await session.prompt(content, mode)
+    const result = await session.prompt(content, 'queue')
     if (!result.ok) throw new Error(`conversation.send failed: ${result.error.code}: ${result.error.message}`)
   }
 

packages/client/ui-conversation/src/client/skeleton/InputBar.tsx

@@ -213,7 +213,7 @@ export function InputBar({
     e.preventDefault()
     if (e.repeat) return // held-down Enter must not machine-gun sends
     if (locked || machineBusy) return
-    inputActions.submit('queue')
+    inputActions.submit()
   }
 
   const onChange = (e: ChangeEvent<HTMLTextAreaElement>): void => {
@@ -355,7 +355,7 @@ export function InputBar({
       return
     }
     /* v8 ignore next -- defensive: the primary button is disabled while empty||disabled, so a click cannot reach the false arm. */
-    if (!empty && !disabled && !machineBusy) inputActions.submit('queue')
+    if (!empty && !disabled && !machineBusy) inputActions.submit()
   }
 
   // The Access seat: the projection-fed permission chip (renders nothing