fix(desktop): preserve the active chat across a sleep/wake gateway reconnect

After a Windows/macOS sleep, the desktop's WS connections drop and the
auto-reconnect reopens the gateway. The route-resume hook treated every
closed->open transition on a new-chat route as 'the user navigated to
/new' and called startFreshSessionDraft, discarding the active runtime
session and parking the previous chat in the sidebar as a detached
session. Keep the active chat when the gateway reopens mid-chat: no
navigation happened, only the transport came back.

Co-authored-by: 0disoft <rodisoft1@gmail.com>

apps/desktop/src/app/session/hooks/use-route-resume.test.tsx

@@ -429,6 +429,58 @@ describe('useRouteResume', () => {
     expect(resumeSession).toHaveBeenCalledWith('session-2', true)
   })
 
+  it('preserves an active new-chat session when the gateway reconnects (#53374)', () => {
+    const resumeSession = vi.fn(async () => undefined)
+    const startFreshSessionDraft = vi.fn()
+    const activeSessionIdRef: MutableRefObject<null | string> = { current: 'runtime-1' }
+    const creatingSessionRef = { current: false }
+    const runtimeIdByStoredSessionIdRef = { current: new Map<string, string>() }
+    const selectedStoredSessionIdRef: MutableRefObject<null | string> = { current: null }
+
+    // First render: gateway CLOSED on the new-chat route with an active runtime
+    // session (the machine just woke; the WS dropped mid-chat).
+    const { rerender } = render(
+      <RouteResumeHarness
+        activeSessionId="runtime-1"
+        activeSessionIdRef={activeSessionIdRef}
+        creatingSessionRef={creatingSessionRef}
+        currentView="chat"
+        freshDraftReady={false}
+        gatewayState="closed"
+        locationPathname="/"
+        resumeSession={resumeSession}
+        routedSessionId={null}
+        runtimeIdByStoredSessionIdRef={runtimeIdByStoredSessionIdRef}
+        selectedStoredSessionId={null}
+        selectedStoredSessionIdRef={selectedStoredSessionIdRef}
+        startFreshSessionDraft={startFreshSessionDraft}
+      />
+    )
+
+    // Sleep/wake: the gateway reopens, nothing navigated. The active chat must
+    // survive — no forced fresh draft, no new session.
+    rerender(
+      <RouteResumeHarness
+        activeSessionId="runtime-1"
+        activeSessionIdRef={activeSessionIdRef}
+        creatingSessionRef={creatingSessionRef}
+        currentView="chat"
+        freshDraftReady={false}
+        gatewayState="open"
+        locationPathname="/"
+        resumeSession={resumeSession}
+        routedSessionId={null}
+        runtimeIdByStoredSessionIdRef={runtimeIdByStoredSessionIdRef}
+        selectedStoredSessionId={null}
+        selectedStoredSessionIdRef={selectedStoredSessionIdRef}
+        startFreshSessionDraft={startFreshSessionDraft}
+      />
+    )
+
+    expect(startFreshSessionDraft).not.toHaveBeenCalled()
+    expect(resumeSession).not.toHaveBeenCalled()
+  })
+
   it('does not re-resume the old session when the new profile gateway opens before /new commits (#68594)', () => {
     const resumeSession = vi.fn(async () => undefined)
     const startFreshSessionDraft = vi.fn()

apps/desktop/src/app/session/hooks/use-route-resume.ts

@@ -193,6 +193,15 @@ export function useRouteResume({
       return
     }
 
+    // A sleep/wake WS reconnect can reopen on a new-chat route while the active
+    // runtime session is still the user's current chat. The gateway re-opened;
+    // nothing navigated. Forcing a fresh draft here is what turned every
+    // Windows/macOS sleep/wake cycle into a brand-new session and parked the
+    // previous chat in the sidebar (#53374). Preserve the active chat instead.
+    if (isNewChatRoute(locationPathname) && gatewayBecameOpen && activeSessionId && !freshDraftReady) {
+      return
+    }
+
     if (
       isNewChatRoute(locationPathname) &&
       !creatingSessionRef.current &&