fix(desktop): /goal arg stays editable, kickoff queues when busy, slash header stops echoing long args

Four symptoms from the same /goal flow on desktop:

- Typing '/goal <text>' sealed the command into a directive chip on
  Space because /goal was registered without args:true, so the goal
  prose rendered awkwardly after a pill. The registry row now matches
  /personality and /tools: the arg stays editable text.

- The slash status header echoed the ENTIRE invocation ('slash:/goal
  <whole goal prose>') in mono, immediately above the backend notice
  that repeats the goal text again, and the kickoff user bubble that
  repeats it a third time. The header now carries just the command
  token (slash:/goal).

- When the session was busy, handleDispatch rendered 'session busy'
  and dropped the dispatch message. For /goal that message is the
  kickoff prompt, and the backend has ALREADY set the goal by then —
  the goal existed but the agent never heard about it, and later turns
  looked goal-unaware (#63352). The busy path now queues the kickoff
  on the composer queue: it sends on settle and is visible/editable in
  the queue panel meanwhile. Falls back to the old message if the
  queue rejects the entry.

- A slash command issued on a fresh draft created the backend session
  with no preview, so the sidebar row sat as 'Untitled session' —
  and when the kickoff was dropped, auto-title never fired either
  (it needs a completed user->assistant exchange). ensureSessionId now
  seeds the preview with the typed command.

Tests: registry row contract, busy-path queueing (kickoff neither
sends mid-turn nor vanishes), and the header-token assertion.

apps/desktop/src/app/session/hooks/use-prompt-actions/index.test.tsx

@@ -6,6 +6,7 @@ import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
 import { getSession } from '@/hermes'
 import { textPart } from '@/lib/chat-messages'
 import { $composerAttachments, $composerDraft, type ComposerAttachment, setComposerDraft } from '@/store/composer'
+import { $queuedPromptsBySession, getQueuedPrompts } from '@/store/composer-queue'
 import { $notifications, clearNotifications } from '@/store/notifications'
 import {
   $busy,
@@ -980,6 +981,113 @@ describe('usePromptActions slash.exec dispatch payloads', () => {
     expect(renderedText).not.toContain('/goal: no output')
   })
 
+  it('queues the /goal kickoff instead of dropping it when the session is busy (#63352)', async () => {
+    // The backend sets the goal the moment slash.exec runs — dropping the
+    // returned kickoff message because busyRef was true left a goal the agent
+    // never heard about. The busy path must park the kickoff on the composer
+    // queue so the settle drain sends it.
+    $queuedPromptsBySession.set({})
+
+    const calls: { method: string; params?: Record<string, unknown> }[] = []
+    const states: Record<string, unknown>[] = []
+    const busyRef = { current: true }
+
+    const requestGateway = vi.fn(async (method: string, params?: Record<string, unknown>) => {
+      calls.push({ method, params })
+
+      if (method === 'slash.exec') {
+        return {
+          type: 'send',
+          notice: '⊙ Goal set (20-turn budget): ship the release notes',
+          message: 'ship the release notes'
+        } as never
+      }
+
+      return {} as never
+    })
+
+    let handle: HarnessHandle | null = null
+    await actRender(
+      <Harness
+        busyRef={busyRef}
+        onReady={h => (handle = h)}
+        onSeedState={s => states.push(s)}
+        refreshSessions={async () => undefined}
+        requestGateway={requestGateway}
+      />
+    )
+
+    await handle!.submitText('/goal ship the release notes')
+
+    // The kickoff must NOT submit mid-turn — and must NOT vanish either.
+    expect(calls.map(c => c.method)).toEqual(['slash.exec'])
+
+    const queued = getQueuedPrompts(RUNTIME_SESSION_ID)
+    expect(queued.map(entry => entry.text)).toEqual(['ship the release notes'])
+
+    const renderedText = states
+      .flatMap(state => {
+        const messages = Array.isArray(state.messages)
+          ? (state.messages as Array<{ parts?: Array<{ text?: string }> }>)
+          : []
+
+        return messages.flatMap(message => (message.parts ?? []).map(part => part.text ?? ''))
+      })
+      .join('\n')
+
+    // The notice still renders, and the busy line reports a queue, not a demand
+    // to /interrupt.
+    expect(renderedText).toContain('⊙ Goal set (20-turn budget): ship the release notes')
+    expect(renderedText).toContain('queued')
+
+    $queuedPromptsBySession.set({})
+  })
+
+  it('slash status header carries the command token, not the full invocation', async () => {
+    // `/goal <long prose>` used to echo the entire invocation in the mono
+    // header AND the goal text again in the backend notice right under it.
+    const states: Record<string, unknown>[] = []
+
+    const requestGateway = vi.fn(async (method: string) => {
+      if (method === 'slash.exec') {
+        return {
+          type: 'send',
+          notice: '⊙ Goal set: build the whole thing',
+          message: 'build the whole thing end to end with tests'
+        } as never
+      }
+
+      return {} as never
+    })
+
+    let handle: HarnessHandle | null = null
+    await actRender(
+      <Harness
+        onReady={h => (handle = h)}
+        onSeedState={s => states.push(s)}
+        refreshSessions={async () => undefined}
+        requestGateway={requestGateway}
+      />
+    )
+
+    await handle!.submitText('/goal build the whole thing end to end with tests')
+
+    const systemTexts = states
+      .flatMap(state => {
+        const messages = Array.isArray(state.messages)
+          ? (state.messages as Array<{ role?: string; parts?: Array<{ text?: string }> }>)
+          : []
+
+        return messages
+          .filter(message => message.role === 'system')
+          .flatMap(message => (message.parts ?? []).map(part => part.text ?? ''))
+      })
+      .join('\n')
+
+    expect(systemTexts).toContain('slash:/goal\n')
+    expect(systemTexts).not.toContain('slash:/goal build the whole thing')
+  })
+
   it('dispatches a slash command with a multiline arg instead of "empty slash command" (#41323, #55510)', async () => {
     const calls: { method: string; params?: Record<string, unknown> }[] = []
     const states: Record<string, unknown>[] = []

apps/desktop/src/app/session/hooks/use-prompt-actions/slash.ts

@@ -17,20 +17,24 @@ import { isMissingRpcMethod } from '@/lib/gateway-rpc'
 import { setSessionYolo } from '@/lib/yolo-session'
 import { openCommandPalettePage } from '@/store/command-palette'
 import { setComposerDraft } from '@/store/composer'
+import { enqueueQueuedPrompt } from '@/store/composer-queue'
 import { dismissNotification, notify, notifyError } from '@/store/notifications'
 import { setPetScale } from '@/store/pet-gallery'
 import { $petGenInput, openPetGenerate } from '@/store/pet-generate'
 import { $activeGatewayProfile, $newChatProfile, ensureGatewayProfile, normalizeProfileKey } from '@/store/profile'
 import {
   $connection,
+  $selectedStoredSessionId,
   $sessions,
   $yoloActive,
+  resolveComposerSessionKey,
   setCurrentUsage,
   setModelPickerOpen,
   setSessionPickerOpen,
   setSessions,
   setYoloActive
 } from '@/store/session'
+import { $sessionStates } from '@/store/session-states'
 
 import type {
   BrowserManageResponse,
@@ -133,10 +137,10 @@ export function useSlashCommand(deps: SlashCommandDeps) {
       // binding momentarily absent (profile swap, reconnect, orphan-reap,
       // timeout) it minted a NEW session, so `/goal status` reported "No active
       // goal" for a goal that was live on the real chat.
-      const ensureSessionId = async (sessionHint?: string) =>
+      const ensureSessionId = async (sessionHint?: string, preview?: null | string) =>
         resolveTargetSessionId({
           activeRuntimeId: activeSessionIdRef.current,
-          createSession: () => createBackendSessionForSend(),
+          createSession: () => createBackendSessionForSend(preview),
           explicitRuntimeId: sessionHint,
           getRuntimeIdForStoredSession,
           requestGateway,
@@ -150,7 +154,11 @@ export function useSlashCommand(deps: SlashCommandDeps) {
       const withSlashOutput = async (
         ctx: SlashActionCtx
       ): Promise<{ render: (text: string) => void; sessionId: string; storedSessionId: string | null } | null> => {
-        const sessionId = await ensureSessionId(ctx.sessionHint)
+        // A slash on a fresh draft creates the backend session; seed the
+        // sidebar preview with the typed command so the row doesn't sit as
+        // "Untitled session" (auto-title only fires after a full exchange,
+        // which a bare exec command never produces).
+        const sessionId = await ensureSessionId(ctx.sessionHint, ctx.command)
 
         if (!sessionId) {
           notify({ kind: 'error', title: copy.sessionUnavailable, message: copy.createSessionFailed })
@@ -162,11 +170,14 @@ export function useSlashCommand(deps: SlashCommandDeps) {
         // output bound to the stored session selected at invocation time.
         const storedSessionId = selectedStoredSessionIdRef.current
 
+        // Header carries the command token only. The full invocation would
+        // duplicate long args — `/goal <prose>` echoed the whole goal in the
+        // mono header, then again in the backend notice right under it.
         const render = (text: string) =>
           appendSessionTextMessage(
             sessionId,
             'system',
-            ctx.recordInput ? slashStatusText(ctx.command, text) : text,
+            ctx.recordInput ? slashStatusText(`/${ctx.name}`, text) : text,
             storedSessionId
           )
 
@@ -184,7 +195,7 @@ export function useSlashCommand(deps: SlashCommandDeps) {
           return
         }
 
-        const { render: renderSlashOutput, sessionId } = resolved
+        const { render: renderSlashOutput, sessionId, storedSessionId } = resolved
 
         if (!isDesktopSlashCommand(name)) {
           renderSlashOutput(desktopSlashUnavailableMessage(name) || `/${name} is not available in the desktop app.`)
@@ -242,7 +253,27 @@ export function useSlashCommand(deps: SlashCommandDeps) {
           }
 
           if (busyRef.current) {
-            renderSlashOutput('session busy — /interrupt the current turn before sending this command')
+            // The backend already executed the command — for `/goal <text>`
+            // the goal is set and `message` is its kickoff prompt. Dropping
+            // it here loses the kickoff silently (the goal exists but the
+            // agent never hears about it, #63352). Queue it on the composer
+            // queue instead: it fires when the running turn settles, and the
+            // queue panel above the composer shows it in the meantime.
+            //
+            // Key off the storedSessionId resolved at invocation time (same
+            // value the output writer is bound to) rather than re-reading the
+            // globals here — a session switch between dispatch and this branch
+            // would otherwise park the kickoff on whichever chat is now in
+            // front. Fall back through the live selection for a session whose
+            // cache entry hasn't landed yet.
+            const storedId = storedSessionId || $sessionStates.get()[sessionId]?.storedSessionId || $selectedStoredSessionId.get()
+            const queueKey = resolveComposerSessionKey(storedId, $sessions.get()) || storedId || sessionId
+
+            if (enqueueQueuedPrompt(queueKey, { attachments: [], text: message })) {
+              renderSlashOutput('session busy — message queued to send when the current turn finishes')
+            } else {
+              renderSlashOutput('session busy — /interrupt the current turn before sending this command')
+            }
 
             return
           }

apps/desktop/src/lib/desktop-slash-commands.test.ts

@@ -141,6 +141,14 @@ describe('desktop slash command curation', () => {
     }
   })
 
+  it('keeps /goal arg text editable instead of sealing it into a chip', () => {
+    // /goal takes free prose (the goal itself) plus subcommands. Without
+    // args:true, Space after the command name committed a sealed directive
+    // chip and the goal text rendered awkwardly after a pill.
+    expect(resolveDesktopCommand('/goal')?.surface).toEqual({ kind: 'exec' })
+    expect(resolveDesktopCommand('/goal')?.args).toBe(true)
+  })
+
   it('routes /journey (and aliases) to the memory graph overlay action', () => {
     expect(resolveDesktopCommand('/journey')?.surface).toEqual({ kind: 'action', action: 'journey' })
     expect(resolveDesktopCommand('/memory-graph')?.surface).toEqual({ kind: 'action', action: 'journey' })

apps/desktop/src/lib/desktop-slash-commands.ts

@@ -209,7 +209,7 @@ const DESKTOP_COMMAND_SPECS: readonly DesktopCommandSpec[] = [
     args: true
   },
   { name: '/debug', description: 'Create a debug report', surface: exec() },
-  { name: '/goal', description: 'Manage the standing goal for this session', surface: exec() },
+  { name: '/goal', description: 'Manage the standing goal for this session', surface: exec(), args: true },
   { name: '/personality', description: 'Switch personality for this session', surface: exec(), args: true },
   {
     name: '/pet',