chore(desktop): drop the dev-only "soft switch" preview from gateway settings

Remove the DEV-gated "Dev · soft switch" ListRow and its previewGatewaySwitch
helper. It was a temporary review affordance for exercising the soft-switch
reconnect; dead-stripped from production, but it doesn't belong in the tree.
wipeSessionListsForGatewaySwitch (the real path) and $gatewaySwitching stay.

apps/desktop/src/app/settings/gateway-settings.tsx

@@ -10,7 +10,6 @@ import { ExternalLink } from '@/lib/external-link'
 import { AlertCircle, Check, Cloud, FileText, Globe, HelpCircle, Loader2, LogIn, Monitor, RefreshCw } from '@/lib/icons'
 import { selectableCardClass } from '@/lib/selectable-card'
 import { cn } from '@/lib/utils'
-import { previewGatewaySwitch } from '@/store/gateway-switch'
 import { notify, notifyError } from '@/store/notifications'
 import { $profiles, refreshActiveProfile } from '@/store/profile'
 
@@ -117,7 +116,6 @@ export function GatewaySettings() {
   const [loading, setLoading] = useState(true)
   const [saving, setSaving] = useState(false)
   const [testing, setTesting] = useState(false)
-  const [previewingSwitch, setPreviewingSwitch] = useState(false)
   const [signingIn, setSigningIn] = useState(false)
   const [state, setState] = useState<GatewaySettingsState>(EMPTY_STATE)
   const [remoteToken, setRemoteToken] = useState('')
@@ -1065,26 +1063,6 @@ export function GatewaySettings() {
           description={g.diagnosticsDesc}
           title={g.diagnostics}
         />
-        {import.meta.env.DEV ? (
-          <ListRow
-            action={
-              <Button
-                disabled={previewingSwitch}
-                onClick={() => {
-                  setPreviewingSwitch(true)
-                  void previewGatewaySwitch().finally(() => setPreviewingSwitch(false))
-                }}
-                size="sm"
-                variant="textStrong"
-              >
-                {previewingSwitch ? <Loader2 className="animate-spin" /> : null}
-                Preview soft switch
-              </Button>
-            }
-            description="Wipe session lists so sidebar skeletons retrigger — no real backend teardown."
-            title="Dev · soft switch"
-          />
-        ) : null}
       </div>
     </SettingsContent>
   )

apps/desktop/src/store/gateway-switch.test.ts

@@ -16,7 +16,7 @@ import {
   setSessionsTotal
 } from '@/store/session'
 
-import { $gatewaySwitching, previewGatewaySwitch, wipeSessionListsForGatewaySwitch } from './gateway-switch'
+import { $gatewaySwitching, wipeSessionListsForGatewaySwitch } from './gateway-switch'
 
 vi.mock('@/lib/query-client', () => ({
   queryClient: { invalidateQueries: vi.fn() }
@@ -54,12 +54,4 @@ describe('wipeSessionListsForGatewaySwitch', () => {
     expect($sessionsLimit.get()).toBe(SIDEBAR_SESSIONS_PAGE_SIZE)
     expect($freshDraftReady.get()).toBe(true)
   })
-
-  it('previewGatewaySwitch holds skeletons then clears loading', async () => {
-    await previewGatewaySwitch(20)
-
-    expect($sessions.get()).toEqual([])
-    expect($sessionsLoading.get()).toBe(false)
-    expect($gatewaySwitching.get()).toBe(false)
-  })
 })

apps/desktop/src/store/gateway-switch.ts

@@ -24,8 +24,6 @@ import {
 // overlay from resurrecting when startHermes re-emits boot progress.
 export const $gatewaySwitching = atom(false)
 
-const PREVIEW_HOLD_MS = 1400
-
 /**
  * Clear gateway-bound session UI so sidebar skeletons retrigger.
  *
@@ -58,26 +56,3 @@ export function wipeSessionListsForGatewaySwitch(): void {
 
   void queryClient.invalidateQueries()
 }
-
-/**
- * Dev review beat: wipe → skeletons for PREVIEW_HOLD_MS → clear loading.
- * Does not tear down a real backend. Fired from the Settings button (Electron
- * has no easy `?query=` entry).
- */
-export async function previewGatewaySwitch(holdMs = PREVIEW_HOLD_MS): Promise<void> {
-  if ($gatewaySwitching.get()) {
-    return
-  }
-
-  $gatewaySwitching.set(true)
-  wipeSessionListsForGatewaySwitch()
-
-  try {
-    await new Promise<void>(resolve => {
-      window.setTimeout(resolve, holdMs)
-    })
-  } finally {
-    setSessionsLoading(false)
-    $gatewaySwitching.set(false)
-  }
-}