added base homescreen-widget setup, working on Android, iOS in progress

android/app/src/main/res/xml/backup_rules.xml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Auto-Backup rules for Android 11 and below.
+     Excludes the home_widget plugin's SharedPreferences file
+     (HomeWidgetPreferences) so the cached timetable — which contains
+     teacher names, room numbers and personal custom events — is not
+     uploaded to the user's Google Drive. -->
+<full-backup-content>
+    <exclude domain="sharedpref" path="HomeWidgetPreferences.xml"/>
+</full-backup-content>

android/app/src/main/res/xml/data_extraction_rules.xml

@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Backup + device-transfer rules for Android 12+.
+     Excludes the home_widget plugin's SharedPreferences file
+     (HomeWidgetPreferences) so the cached timetable — which contains
+     teacher names, room numbers and personal custom events — is not
+     uploaded to the user's Google Drive or transferred to a new device.
+     The widget repopulates from a fresh Webuntis fetch after sign-in. -->
+<data-extraction-rules>
+    <cloud-backup>
+        <exclude domain="sharedpref" path="HomeWidgetPreferences.xml"/>
+    </cloud-backup>
+    <device-transfer>
+        <exclude domain="sharedpref" path="HomeWidgetPreferences.xml"/>
+    </device-transfer>
+</data-extraction-rules>

android/app/src/main/res/xml/timetable_day_widget_info.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<appwidget-provider xmlns:android="http://schemas.android.com/apk/res/android"
+    android:initialLayout="@layout/widget_placeholder"
+    android:minWidth="110dp"
+    android:minHeight="180dp"
+    android:targetCellWidth="2"
+    android:targetCellHeight="5"
+    android:resizeMode="horizontal|vertical"
+    android:widgetCategory="home_screen"
+    android:updatePeriodMillis="0"
+    android:description="@string/widget_day_description"
+    android:previewLayout="@layout/widget_day_preview" />

android/app/src/main/res/xml/timetable_week_widget_info.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<appwidget-provider xmlns:android="http://schemas.android.com/apk/res/android"
+    android:initialLayout="@layout/widget_placeholder"
+    android:minWidth="320dp"
+    android:minHeight="240dp"
+    android:targetCellWidth="5"
+    android:targetCellHeight="5"
+    android:resizeMode="horizontal|vertical"
+    android:widgetCategory="home_screen"
+    android:updatePeriodMillis="0"
+    android:description="@string/widget_week_description"
+    android:previewLayout="@layout/widget_week_preview" />