feat(notifications): initialize Firebase Messaging and Capacitor push on native

Add firebaseMessagingClient to ensure the Firebase app is created from VITE_FIREBASE_*,
wire PushNotifications (listeners, requestPermissions, register) before token work,
and call getMessaging/getToken/onMessage when firebase/messaging is supported. Hook
startup from main.capacitor and set PushNotifications presentationOptions in
capacitor.config. Depend on firebase and @capacitor/push-notifications.

android/app/capacitor.build.gradle

@@ -15,6 +15,7 @@ dependencies {
     implementation project(':capacitor-camera')
     implementation project(':capacitor-clipboard')
     implementation project(':capacitor-filesystem')
+    implementation project(':capacitor-push-notifications')
     implementation project(':capacitor-share')
     implementation project(':capacitor-status-bar')
     implementation project(':capawesome-capacitor-file-picker')

android/app/src/main/assets/capacitor.config.json

@@ -16,6 +16,13 @@
 				]
 			}
 		},
+		"PushNotifications": {
+			"presentationOptions": [
+				"badge",
+				"sound",
+				"alert"
+			]
+		},
 		"SplashScreen": {
 			"launchShowDuration": 3000,
 			"launchAutoHide": true,

android/app/src/main/assets/capacitor.plugins.json

@@ -23,6 +23,10 @@
 		"pkg": "@capacitor/filesystem",
 		"classpath": "com.capacitorjs.plugins.filesystem.FilesystemPlugin"
 	},
+	{
+		"pkg": "@capacitor/push-notifications",
+		"classpath": "com.capacitorjs.plugins.pushnotifications.PushNotificationsPlugin"
+	},
 	{
 		"pkg": "@capacitor/share",
 		"classpath": "com.capacitorjs.plugins.share.SharePlugin"