feat: Integrate Firebase Authentication and Firestore

- Added Firebase configuration to Android and iOS projects.
- Created `google-services.json` and `GoogleService-Info.plist` for Firebase setup.
- Implemented `AuthService` for handling user authentication with Firebase.
- Updated `UserProvider` to manage user data with Firestore.
- Refactored `ProfileContent`, `LoginPage`, and `SignUpPage` to use the new authentication service.
- Removed the old `UserService` and replaced it with Firestore-based user management.
- Added Firebase options in `firebase_options.dart` for platform-specific configurations.
- Updated dependencies in `pubspec.yaml` for Firebase packages.

android/app/build.gradle.kts

@@ -1,5 +1,8 @@
 plugins {
     id("com.android.application")
+    // START: FlutterFire Configuration
+    id("com.google.gms.google-services")
+    // END: FlutterFire Configuration
     id("kotlin-android")
     // The Flutter Gradle Plugin must be applied after the Android and Kotlin Gradle plugins.
     id("dev.flutter.flutter-gradle-plugin")

android/app/google-services.json

@@ -0,0 +1,54 @@
+{
+  "project_info": {
+    "project_number": "521527250907",
+    "project_id": "travelmate-a47f5",
+    "storage_bucket": "travelmate-a47f5.firebasestorage.app"
+  },
+  "client": [
+    {
+      "client_info": {
+        "mobilesdk_app_id": "1:521527250907:android:be3db7fc84f053ec7da1fe",
+        "android_client_info": {
+          "package_name": "com.example.travel_mate"
+        }
+      },
+      "oauth_client": [
+        {
+          "client_id": "521527250907-lqgj1lmfcsjusm2be9r6kpuanq3jvjcd.apps.googleusercontent.com",
+          "client_type": 1,
+          "android_info": {
+            "package_name": "com.example.travel_mate",
+            "certificate_hash": "9b7e3f14f0fcae0034ed977b5d40305b1812308d"
+          }
+        },
+        {
+          "client_id": "521527250907-j0kt1hc8hc7qc2kedp4akehau754cn5d.apps.googleusercontent.com",
+          "client_type": 3
+        }
+      ],
+      "api_key": [
+        {
+          "current_key": "AIzaSyAON_ol0Jr34tKbETvdDK9JCQdKNawxBeQ"
+        }
+      ],
+      "services": {
+        "appinvite_service": {
+          "other_platform_oauth_client": [
+            {
+              "client_id": "521527250907-j0kt1hc8hc7qc2kedp4akehau754cn5d.apps.googleusercontent.com",
+              "client_type": 3
+            },
+            {
+              "client_id": "521527250907-3i1qe2656eojs8k9hjdi573j09i9p41m.apps.googleusercontent.com",
+              "client_type": 2,
+              "ios_info": {
+                "bundle_id": "com.example.travelMate"
+              }
+            }
+          ]
+        }
+      }
+    }
+  ],
+  "configuration_version": "1"
+}

android/settings.gradle.kts

@@ -20,6 +20,9 @@ pluginManagement {
 plugins {
     id("dev.flutter.flutter-plugin-loader") version "1.0.0"
     id("com.android.application") version "8.9.1" apply false
+    // START: FlutterFire Configuration
+    id("com.google.gms.google-services") version("4.3.15") apply false
+    // END: FlutterFire Configuration
     id("org.jetbrains.kotlin.android") version "2.1.0" apply false
 }