feat: new onboarding screens (#4)

Changelog:
- Add a custom splash screen
- Redesign the onboarding screen
- Improve UX for the new and import identity screens

Reviewed-on: #4

composeApp/src/androidMain/composeResources/drawable/coop.xml

@@ -1,18 +1,3 @@
-<!--
-  ~ Copyright (C) 2026 The Android Open Source Project
-  ~
-  ~ Licensed under the Apache License, Version 2.0 (the "License");
-  ~ you may not use this file except in compliance with the License.
-  ~ You may obtain a copy of the License at
-  ~
-  ~      http://www.apache.org/licenses/LICENSE-2.0
-  ~
-  ~ Unless required by applicable law or agreed to in writing, software
-  ~ distributed under the License is distributed on an "AS IS" BASIS,
-  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-  ~ See the License for the specific language governing permissions and
-  ~ limitations under the License.
-  -->
 <vector xmlns:android="http://schemas.android.com/apk/res/android"
     android:width="750dp"
     android:height="750dp"