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/Mesh.vue

@@ -346,7 +346,7 @@ function truncatePubkey(hex: string | null): string {
       <!-- LEFT COLUMN: Status + Peers -->
       <div class="mesh-left" :class="{ 'mobile-hidden': mobileShowChat }">
         <!-- Device Status -->
-        <div class="glass-card mesh-status-card">
+        <div data-controller-container tabindex="0" class="glass-card mesh-status-card">
           <div class="mesh-status-header">
             <div class="mesh-status-indicator" :class="mesh.status?.device_connected ? 'connected' : 'disconnected'" />
             <h2 class="mesh-section-title">Device</h2>
@@ -429,7 +429,7 @@ function truncatePubkey(hex: string | null): string {
         </div>
 
         <!-- Peers list -->
-        <div class="glass-card mesh-peers-card">
+        <div data-controller-container tabindex="0" class="glass-card mesh-peers-card">
           <h2 class="mesh-section-title">Peers <span class="mesh-peer-count">{{ mesh.peers.length }}</span></h2>
 
           <div v-if="mesh.peers.length === 0 && !mesh.status?.device_connected" class="mesh-empty">
@@ -512,7 +512,7 @@ function truncatePubkey(hex: string | null): string {
         </div>
 
         <!-- Chat Panel -->
-        <div v-if="showChatPanel" class="glass-card mesh-chat-card">
+        <div v-if="showChatPanel" data-controller-container tabindex="0" class="glass-card mesh-chat-card">
           <div v-if="!hasActiveChat" class="mesh-chat-empty">
             <div class="mesh-chat-empty-icon">&#x1F4E1;</div>
             <p>Select a peer or channel to chat</p>