feat: add AppLayout, BrandLogo, ProfileMenu, and RouteBadge components

- Implemented AppLayout component for application shell with navigation and sidebar.
- Created BrandLogo component to display the application logo.
- Developed ProfileMenu component for user profile management with dropdown functionality.
- Added RouteBadge component to visually represent route numbers with color coding.

style: add CSS styles for Dashboard and Routes pages

- Introduced Dashboard.css for styling the dashboard layout and components.
- Created RoutesPage.css for styling the routes page, including filters and table layout.
- Added SchedulesPage.css for styling the schedules layout and route options.

backend/src/services/alertNotificationService.js

@@ -1,6 +1,5 @@
 const {
   DEFAULT_FCM_TOPIC,
-  DEFAULT_FCM_ANDROID_CHANNEL_ID,
   getFirebaseConfig,
   getFirebaseMessaging
 } = require('../config/firebase');
@@ -91,14 +90,9 @@ function isAlertActive(alert = {}) {
 function buildAlertCreatedMessage(alert, options = {}) {
   const alertId = getAlertId(alert);
   const topic = options.topic || DEFAULT_FCM_TOPIC;
-  const channelId = options.androidChannelId || options.channelId || DEFAULT_FCM_ANDROID_CHANNEL_ID;
 
   return {
     topic,
-    notification: {
-      title: getNotificationTitle(alert),
-      body: getNotificationBody(alert)
-    },
     data: {
       event: 'alert_created',
       alertId,
@@ -106,14 +100,12 @@ function buildAlertCreatedMessage(alert, options = {}) {
       routeId: getRouteId(alert),
       routeNumber: getRouteNumber(alert),
       startTime: toIsoString(firstDefined(alert.start_time, alert.startTime)),
-      endTime: toIsoString(firstDefined(alert.end_time, alert.endTime))
+      endTime: toIsoString(firstDefined(alert.end_time, alert.endTime)),
+      title: getNotificationTitle(alert),
+      body: getNotificationBody(alert)
     },
     android: {
-      priority: 'high',
-      notification: {
-        channelId,
-        tag: `alert_${alertId}`
-      }
+      priority: 'high'
     }
   };
 }
@@ -131,14 +123,12 @@ class AlertNotificationService {
 
     this.enabled = options.enabled === undefined ? firebaseConfig.enabled : options.enabled;
     this.topic = options.topic || firebaseConfig.topic;
-    this.androidChannelId = options.androidChannelId || options.channelId || firebaseConfig.androidChannelId;
     this.logger = options.logger || getDefaultLogger();
     this.getMessaging = options.getMessaging || options.messagingFactory || (() => (
       options.messaging || getFirebaseMessaging({
         ...firebaseConfig,
         enabled: this.enabled,
-        topic: this.topic,
-        androidChannelId: this.androidChannelId
+        topic: this.topic
       })
     ));
   }
@@ -160,10 +150,7 @@ class AlertNotificationService {
         throw new Error('Firebase Messaging is unavailable');
       }
 
-      const message = buildAlertCreatedMessage(alert, {
-        topic: this.topic,
-        androidChannelId: this.androidChannelId
-      });
+      const message = buildAlertCreatedMessage(alert, { topic: this.topic });
       const messageId = await messaging.send(message);
       const normalizedMessageId = toDataString(messageId);