feat: add nerve to stats bar, gym nav link, nerve dashboard card

- Add nerve chip to stats-bar showing current/max nerve with purple brain icon
- Add Gym link to sidebar navigation with muscle emoji and active state
- Add Nerve card to dashboard with progress bar, description, and Go to Gym link

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

resources/views/game/dashboard.blade.php

@@ -53,6 +53,28 @@
             </div>
         </div>
 
+        {{-- Nerve --}}
+        <div class="bg-syndicate-800 border border-syndicate-700 rounded-lg p-6">
+            <h3 class="font-display text-lg font-semibold text-gray-100 mb-4">Nerve</h3>
+            <div class="space-y-3">
+                <div class="flex justify-between text-sm">
+                    <span class="text-gray-400">Available</span>
+                    <span class="text-purple-400 font-medium">{{ $character->nerve }} / {{ $character->max_nerve }}</span>
+                </div>
+                <div class="w-full bg-syndicate-700 rounded-full h-2">
+                    <div class="bg-purple-600 h-2 rounded-full transition-all"
+                         style="width: {{ $character->nerve_percentage }}%"></div>
+                </div>
+                <p class="text-xs text-gray-600">
+                    Nerve gates crime volume. Recharges over time and fully refills at midnight.
+                </p>
+                <a href="{{ route('game.gym.index') }}"
+                   class="block w-full text-center bg-syndicate-700 hover:bg-syndicate-600 text-gray-300 py-2 px-4 rounded text-sm transition mt-2">
+                    Go to Gym
+                </a>
+            </div>
+        </div>
+
         {{-- Finances --}}
         <div class="bg-syndicate-800 border border-syndicate-700 rounded-lg p-6">
             <h3 class="font-display text-lg font-semibold text-gray-100 mb-4">Finances</h3>