feat: gamepad navigation rewrite, focus styling, container grid system

- Rewrite useControllerNav.ts with clean console-style navigation:
  Sidebar (up/down wrap, right→containers, left→nothing),
  Container tile grid (spatial nav, no wrap at edges),
  Nav bar support (up from containers, down to grid),
  Inner controls (enter drills in, escape exits, trapped arrows)
- Add data-controller-container to Mesh, Fleet, Settings pages
- Fix Home.vue fragment (modals outside root div) causing Vue warnings
- Remove skip-to-content link (handled by controller nav)
- Orange ambient glow focus styling matching glass aesthetic
- Disable PWA service worker in dev mode (fixes HMR caching)
- Add gamepad-nav skill and GAMEPAD-NAV-MAP.md spec document
- 39 tests covering all navigation patterns

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

neode-ui/src/views/fleet/FleetOverviewCards.vue

@@ -1,6 +1,6 @@
 <template>
   <div class="grid grid-cols-2 lg:grid-cols-5 gap-4 mb-6">
-    <div class="monitoring-stat-card">
+    <div data-controller-container tabindex="0" class="monitoring-stat-card">
       <p class="text-xs text-white/50 uppercase tracking-wide">Total Nodes</p>
       <p class="text-2xl font-bold text-white">{{ nodeCount }}</p>
       <p class="text-xs text-white/40">
@@ -8,22 +8,22 @@
         <span class="ml-1 fleet-dot-offline"></span> {{ offlineCount }} offline
       </p>
     </div>
-    <div class="monitoring-stat-card">
+    <div data-controller-container tabindex="0" class="monitoring-stat-card">
       <p class="text-xs text-white/50 uppercase tracking-wide">Fleet Health</p>
       <p class="text-2xl font-bold text-white">{{ fleetHealthPct }}%</p>
       <p class="text-xs text-white/40">{{ healthyCount }}/{{ nodeCount }} no alerts</p>
     </div>
-    <div class="monitoring-stat-card">
+    <div data-controller-container tabindex="0" class="monitoring-stat-card">
       <p class="text-xs text-white/50 uppercase tracking-wide">Avg CPU</p>
       <p class="text-2xl font-bold text-white" :class="healthTextClass(avgCpu)">{{ avgCpu.toFixed(1) }}%</p>
       <p class="text-xs text-white/40">across fleet</p>
     </div>
-    <div class="monitoring-stat-card">
+    <div data-controller-container tabindex="0" class="monitoring-stat-card">
       <p class="text-xs text-white/50 uppercase tracking-wide">Avg RAM</p>
       <p class="text-2xl font-bold text-white" :class="healthTextClass(avgMem)">{{ avgMem.toFixed(1) }}%</p>
       <p class="text-xs text-white/40">across fleet</p>
     </div>
-    <div class="monitoring-stat-card">
+    <div data-controller-container tabindex="0" class="monitoring-stat-card">
       <p class="text-xs text-white/50 uppercase tracking-wide">Avg Disk</p>
       <p class="text-2xl font-bold text-white" :class="healthTextClass(avgDisk)">{{ avgDisk.toFixed(1) }}%</p>
       <p class="text-xs text-white/40">across fleet</p>