refactor: split Marketplace, Server, Home, AppDetails views; minor frontend quality fixes

- F29-F32: Split 4 views (Marketplace 1293→505, Server 1132→486, Home 1059→394, AppDetails 1036→386)
- F20: Add aria-current="page" to Dashboard nav links
- F21: Add 150ms search debounce in Marketplace and Apps views
- F22: Reduce backdrop-filter blur to 8px on mobile for GPU performance
- F23: Track and clear WebSocket connect check interval in all paths

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

neode-ui/src/views/Dashboard.vue

@@ -80,6 +80,7 @@
               v-for="(item, idx) in desktopNavItems"
               :key="item.path"
               :to="item.path"
+              aria-current-value="page"
               class="sidebar-nav-item flex items-center gap-3 px-4 py-3 rounded-lg text-white/80 hover:bg-white/10 hover:text-white transition-colors"
               :class="{ 'nav-tab-active': item.isCombined && (route.path.includes('/apps') || route.path.includes('/marketplace') || route.path.includes('/discover') || route.path.includes('/app-session') || (item.path === '/dashboard/apps' && !!appLauncher.panelAppId)) }"
               :exact-active-class="item.isCombined ? undefined : 'nav-tab-active'"
@@ -298,6 +299,7 @@
           v-for="item in mobileNavItems"
           :key="item.path"
           :to="item.path"
+          aria-current-value="page"
           @click="appLauncher.closePanel()"
           class="flex flex-col items-center justify-center w-full py-1.5 rounded-lg text-white/70 transition-all duration-300 relative z-10 gap-0.5"
           :class="{