feat(demo): typing splash + intro on every fresh visit; neutral desktop Cloud tabs

- Demo boots at '/' (first visit or a browser refresh) always start with
  the typing splash into the onboarding intro — the per-calendar-day
  gate is gone. In-session SPA navigation never replays it, and
  deep-route refreshes keep the visitor's place.
- Cloud top-level tabs return to the standard mode-switcher style on
  desktop; the orange full-width switcher stays mobile-only.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

neode-ui/src/views/OnboardingIntro.vue

@@ -56,16 +56,13 @@ import { ref, onMounted } from 'vue'
 import { useRouter } from 'vue-router'
 import AnimatedLogo from '@/components/AnimatedLogo.vue'
 import { playNavSound } from '@/composables/useNavSounds'
-import { IS_DEMO, markDemoIntroSeen } from '@/composables/useDemoIntro'
+import { IS_DEMO } from '@/composables/useDemoIntro'
 
 const router = useRouter()
 const ctaButton = ref<HTMLButtonElement | null>(null)
 const isDemo = IS_DEMO
 
 onMounted(() => {
-  // Demo: once the visitor has seen the intro today, don't auto-replay it again
-  // until tomorrow (they can still use "Replay Intro" on the login screen).
-  if (IS_DEMO) markDemoIntroSeen()
   // Auto-focus after entry animation completes (1.4s animation delay + 0.6s duration)
   setTimeout(() => {
     ctaButton.value?.focus({ preventScroll: true })