fix(desktop): submit first message after session creation

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

@@ -1294,7 +1294,14 @@ describe('usePromptActions sleep/wake session recovery', () => {
   })
 
   it('still creates a new session for a genuine new-chat draft (no stored session selected)', async () => {
-    const createBackendSessionForSend = vi.fn(async () => RUNTIME_SESSION_ID)
+    const activeSessionIdRef: MutableRefObject<string | null> = { current: null }
+
+    const createBackendSessionForSend = vi.fn(async () => {
+      activeSessionIdRef.current = RUNTIME_SESSION_ID
+
+      return RUNTIME_SESSION_ID
+    })
+
     const calls: string[] = []
 
     const requestGateway = vi.fn(async (method: string) => {
@@ -1307,6 +1314,7 @@ describe('usePromptActions sleep/wake session recovery', () => {
     render(
       <Harness
         activeSessionId={null}
+        activeSessionIdRef={activeSessionIdRef}
         createBackendSessionForSend={createBackendSessionForSend}
         onReady={h => (handle = h)}
         refreshSessions={async () => undefined}
@@ -1321,6 +1329,99 @@ describe('usePromptActions sleep/wake session recovery', () => {
     expect(createBackendSessionForSend).toHaveBeenCalledTimes(1)
     expect(calls).not.toContain('session.resume')
   })
+
+  it('submits the first message after session creation routes to the newly titled chat', async () => {
+    const activeSessionIdRef: MutableRefObject<string | null> = { current: null }
+    const selectedStoredSessionIdRef: MutableRefObject<string | null> = { current: null }
+    let routeToken = '/'
+    const calls: { method: string; params?: Record<string, unknown> }[] = []
+
+    const createBackendSessionForSend = vi.fn(async () => {
+      activeSessionIdRef.current = RUNTIME_SESSION_ID
+      selectedStoredSessionIdRef.current = STORED_SESSION_ID
+      routeToken = `/${STORED_SESSION_ID}`
+
+      return RUNTIME_SESSION_ID
+    })
+
+    const requestGateway = vi.fn(async (method: string, params?: Record<string, unknown>) => {
+      calls.push({ method, params })
+
+      return {} as never
+    })
+
+    let handle: HarnessHandle | null = null
+    render(
+      <Harness
+        activeSessionId={null}
+        activeSessionIdRef={activeSessionIdRef}
+        createBackendSessionForSend={createBackendSessionForSend}
+        getRouteToken={() => routeToken}
+        onReady={h => (handle = h)}
+        refreshSessions={async () => undefined}
+        requestGateway={requestGateway}
+        selectedStoredSessionIdRef={selectedStoredSessionIdRef}
+        storedSessionId={null}
+      />
+    )
+
+    const ok = await handle!.submitText('first message becomes the title and must also send')
+
+    expect(ok).toBe(true)
+    expect(calls).toContainEqual({
+      method: 'prompt.submit',
+      params: {
+        session_id: RUNTIME_SESSION_ID,
+        text: 'first message becomes the title and must also send'
+      }
+    })
+  })
+
+  it('aborts when the user switches chats during post-create async work', async () => {
+    const activeSessionIdRef: MutableRefObject<string | null> = { current: null }
+    const selectedStoredSessionIdRef: MutableRefObject<string | null> = { current: null }
+    let routeToken = '/'
+    const calls: string[] = []
+
+    const createBackendSessionForSend = vi.fn(async () => {
+      // session.create performs its intentional promotion first.
+      activeSessionIdRef.current = RUNTIME_SESSION_ID
+      selectedStoredSessionIdRef.current = STORED_SESSION_ID
+      routeToken = `/${STORED_SESSION_ID}`
+      await Promise.resolve()
+
+      // Then the user selects another chat while post-create work is pending.
+      activeSessionIdRef.current = 'runtime-session-b'
+      selectedStoredSessionIdRef.current = 'stored-session-b'
+      routeToken = '/stored-session-b'
+
+      return RUNTIME_SESSION_ID
+    })
+
+    const requestGateway = vi.fn(async (method: string) => {
+      calls.push(method)
+
+      return {} as never
+    })
+
+    let handle: HarnessHandle | null = null
+    render(
+      <Harness
+        activeSessionId={null}
+        activeSessionIdRef={activeSessionIdRef}
+        createBackendSessionForSend={createBackendSessionForSend}
+        getRouteToken={() => routeToken}
+        onReady={h => (handle = h)}
+        refreshSessions={async () => undefined}
+        requestGateway={requestGateway}
+        selectedStoredSessionIdRef={selectedStoredSessionIdRef}
+        storedSessionId={null}
+      />
+    )
+
+    expect(await handle!.submitText('must not follow the user into chat B')).toBe(false)
+    expect(calls).not.toContain('prompt.submit')
+  })
 })
 
 describe('usePromptActions submit session-context isolation (#54527)', () => {

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

@@ -15,6 +15,7 @@ import { clearNotifications, notify, notifyError } from '@/store/notifications'
 import { requestDesktopOnboarding } from '@/store/onboarding'
 import { setAwaitingResponse, setBusy, setMessages } from '@/store/session'
 
+import { sessionRoute } from '../../../routes'
 import type { ClientSessionState } from '../../../types'
 
 import {
@@ -120,11 +121,11 @@ export function useSubmitPrompt(deps: SubmitPromptDeps) {
       // redirect the user's text into a different chat (#54527).
       const startingActiveSessionId = activeSessionIdRef.current
       const startingStoredSessionId = selectedStoredSessionIdRef.current
-      const startingRouteToken = getRouteToken()
+      let expectedStoredSessionId = startingStoredSessionId
+      let expectedRouteToken = getRouteToken()
 
       const sessionContextDrifted = (): boolean =>
-        selectedStoredSessionIdRef.current !== startingStoredSessionId ||
-        getRouteToken() !== startingRouteToken
+        selectedStoredSessionIdRef.current !== expectedStoredSessionId || getRouteToken() !== expectedRouteToken
 
       // One submit in flight per session — drop any concurrent re-fire so a
       // stalled turn can't stack the same prompt into multiple real turns.
@@ -281,10 +282,6 @@ export function useSubmitPrompt(deps: SubmitPromptDeps) {
           return false
         }
 
-        if (sessionContextDrifted()) {
-          return abortForSessionSwitch(sessionId)
-        }
-
         if (!sessionId) {
           dropOptimistic(null)
           releaseBusy()
@@ -293,6 +290,26 @@ export function useSubmitPrompt(deps: SubmitPromptDeps) {
           return false
         }
 
+        // session.create deliberately promotes the fresh draft onto its new
+        // stored-session route. Accept only that exact promotion: post-create
+        // work (for example applying an armed YOLO mode) can await before this
+        // function regains control, so the user may genuinely switch chats in
+        // that window. Never rebase the guard onto an unrelated destination.
+        const promotedStoredSessionId = selectedStoredSessionIdRef.current
+        const promotedRouteToken = getRouteToken()
+
+        const promotionIsCurrent =
+          activeSessionIdRef.current === sessionId &&
+          (promotedStoredSessionId
+            ? promotedRouteToken === sessionRoute(promotedStoredSessionId)
+            : promotedRouteToken === expectedRouteToken)
+
+        if (!promotionIsCurrent) {
+          return abortForSessionSwitch(sessionId)
+        }
+
+        expectedStoredSessionId = promotedStoredSessionId
+        expectedRouteToken = promotedRouteToken
         seedOptimistic(sessionId)
       }