feat(test-app): add notification delivery indicator

- Add visual indicator when notification is received (shows for 30s)
- Poll notification status every 5 seconds to detect recent deliveries
- Add helpful message in test notification success about checking top of screen
- Improve user feedback for notification testing workflow

test-apps/android-test-app/app/src/main/assets/public/index.html

@@ -62,6 +62,11 @@
                 <div id="pluginStatusContent" style="margin-top: 8px;">
                     Loading plugin status...
                 </div>
+                <div id="notificationReceivedIndicator" style="margin-top: 8px; padding: 8px; background: rgba(0, 255, 0, 0.2); border-radius: 5px; display: none;">
+                    <strong>🔔 Notification Received!</strong><br>
+                    <span id="notificationReceivedTime"></span><br>
+                    <small>Check the top of your screen for the notification banner</small>
+                </div>
             </div>
         </div>
         
@@ -232,7 +237,8 @@
                     const notificationTimeReadable = notificationTime.toLocaleTimeString();
                     status.innerHTML = '✅ Notification scheduled!<br>' +
                                      '📥 Prefetch: ' + prefetchTimeReadable + ' (' + prefetchTimeString + ')<br>' +
-                                     '🔔 Notification: ' + notificationTimeReadable + ' (' + notificationTimeString + ')';
+                                     '🔔 Notification: ' + notificationTimeReadable + ' (' + notificationTimeString + ')<br><br>' +
+                                     '<small>💡 When the notification fires, look for a banner at the <strong>top of your screen</strong>.</small>';
                     status.style.background = 'rgba(0, 255, 0, 0.3)'; // Green background
                     // Refresh plugin status display
                     setTimeout(() => loadPluginStatus(), 500);
@@ -411,6 +417,39 @@
             }
         }
         
+        // Check for notification delivery periodically
+        function checkNotificationDelivery() {
+            if (!window.DailyNotification) return;
+            
+            window.DailyNotification.getNotificationStatus()
+                .then(result => {
+                    if (result.lastNotificationTime) {
+                        const lastTime = new Date(result.lastNotificationTime);
+                        const now = new Date();
+                        const timeDiff = now - lastTime;
+                        
+                        // If notification was received in the last 2 minutes, show indicator
+                        if (timeDiff > 0 && timeDiff < 120000) {
+                            const indicator = document.getElementById('notificationReceivedIndicator');
+                            const timeSpan = document.getElementById('notificationReceivedTime');
+                            
+                            if (indicator && timeSpan) {
+                                indicator.style.display = 'block';
+                                timeSpan.textContent = `Received at ${lastTime.toLocaleTimeString()}`;
+                                
+                                // Hide after 30 seconds
+                                setTimeout(() => {
+                                    indicator.style.display = 'none';
+                                }, 30000);
+                            }
+                        }
+                    }
+                })
+                .catch(error => {
+                    // Silently fail - this is just for visual feedback
+                });
+        }
+        
         // Load plugin status automatically on page load
         window.addEventListener('load', () => {
             console.log('Page loaded, loading plugin status...');
@@ -419,6 +458,9 @@
                 loadPluginStatus();
                 loadPermissionStatus();
                 loadChannelStatus();
+                
+                // Check for notification delivery every 5 seconds
+                setInterval(checkNotificationDelivery, 5000);
             }, 500);
         });