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

android/app/src/main/AndroidManifest.xml

@@ -2,7 +2,9 @@
     <application
         android:label="Marianum Fulda"
         android:name="${applicationName}"
-        android:icon="@mipmap/ic_launcher">
+        android:icon="@mipmap/ic_launcher"
+        android:fullBackupContent="@xml/backup_rules"
+        android:dataExtractionRules="@xml/data_extraction_rules">
         <activity
             android:name=".MainActivity"
             android:exported="true"
@@ -29,6 +31,32 @@
         <meta-data
             android:name="flutterEmbedding"
             android:value="2" />
+
+        <!-- Receiver classes live at the package root (NOT under .widgets) because
+             the home_widget Flutter plugin resolves them as <app-package>.<name>. -->
+        <receiver
+            android:name="eu.mhsl.marianum.mobile.client.TimetableDayWidget"
+            android:label="@string/widget_day_label"
+            android:exported="true">
+            <intent-filter>
+                <action android:name="android.appwidget.action.APPWIDGET_UPDATE" />
+            </intent-filter>
+            <meta-data
+                android:name="android.appwidget.provider"
+                android:resource="@xml/timetable_day_widget_info" />
+        </receiver>
+
+        <receiver
+            android:name="eu.mhsl.marianum.mobile.client.TimetableWeekWidget"
+            android:label="@string/widget_week_label"
+            android:exported="true">
+            <intent-filter>
+                <action android:name="android.appwidget.action.APPWIDGET_UPDATE" />
+            </intent-filter>
+            <meta-data
+                android:name="android.appwidget.provider"
+                android:resource="@xml/timetable_week_widget_info" />
+        </receiver>
     </application>
     <!-- Required to query activities that can process text, see:
          https://developer.android.com/training/package-visibility?hl=en and
@@ -42,4 +70,7 @@
         </intent>
     </queries>
     <uses-permission android:name="android.permission.INTERNET"/>
+    <!-- Workmanager periodic widget refresh needs to reschedule after device
+         reboot, otherwise the widget freezes until the user opens the app. -->
+    <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"/>
 </manifest>