Add Android APK download feature

- Add sidebar nav item and dashboard stat card for APK download
- Add android/ to .gitignore

views/dashboard/index.php

@@ -52,6 +52,13 @@ $recentActivity = $recentActivity ?? [];
             <span class="stat-label">Avg Disk</span>
         </div>
     </div>
+    <a href="/sysadmin.apk" class="stat-card stat-card-info" download style="text-decoration:none; cursor:pointer;">
+        <div class="stat-icon"><i class="fas fa-download"></i></div>
+        <div class="stat-info">
+            <span class="stat-value">v1.0</span>
+            <span class="stat-label">Android App</span>
+        </div>
+    </a>
 </div>
 
 <div class="dashboard-grid">