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/Cloud.vue

@@ -6,12 +6,12 @@
       <!-- Desktop: page tabs + category tabs + search on one row -->
       <div class="app-header-desktop items-center gap-4">
         <div class="flex-shrink-0">
-          <div class="cloud-tab-switcher hidden md:inline-flex">
+          <div class="mode-switcher hidden md:inline-flex">
             <button
               v-for="tab in TABS"
               :key="tab.id"
-              class="cloud-tab-btn"
-              :class="{ 'cloud-tab-btn-active': activeTab === tab.id }"
+              class="mode-switcher-btn"
+              :class="{ 'mode-switcher-btn-active': activeTab === tab.id }"
               @click="activeTab = tab.id"
             >{{ tab.name }}</button>
           </div>
@@ -789,8 +789,9 @@ defineExpose({ loadPeers })
 </script>
 
 <style scoped>
-/* Top-level tab switcher — deliberately a DIFFERENT look from the neutral
-   category pills below it: orange-tinted container + active state. */
+/* Mobile-only top-level tab switcher — deliberately a DIFFERENT look from the
+   neutral category pills below it (orange tint). Desktop keeps the standard
+   mode-switcher styling. */
 .cloud-tab-switcher {
   gap: 2px;
   padding: 3px;