add button for installing PWA

web/js/sections/home.js

@@ -104,6 +104,25 @@ const HomeSection = {
             </button>
           </div>
         </div>
+
+        <!-- PWA Install App card (hidden by default) -->
+        <div class="card" id="home-pwa-install-card" style="display: none; margin-top: 16px;">
+          <div class="card-header">
+            <span class="card-title">Install App</span>
+          </div>
+          <p style="font-size: 0.82rem; color: var(--text-secondary); margin-bottom: 12px; line-height: 1.5;">
+            Install WijiBoard to your device for a native app experience and full-screen control.
+          </p>
+          <button class="btn btn-primary" id="home-btn-install-pwa" style="width: 100%; justify-content: center;">
+            <svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" style="margin-right: 8px;">
+              <path d="M21 15v4a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2v-4"></path>
+              <polyline points="7 10 12 15 17 10"></polyline>
+              <line x1="12" y1="15" x2="12" y2="3"></line>
+            </svg>
+            Install WijiBoard
+          </button>
+        </div>
+
       </div>
     `;