chore: Crop shortcut file on android and cache it

lib/utils/shortcut_memory_icon.dart

@@ -0,0 +1,36 @@
+import 'dart:convert';
+import 'dart:typed_data';
+
+import 'package:image/image.dart';
+import 'package:matrix/matrix.dart';
+
+extension ShortcutMemoryIcon on Uint8List {
+  Future<String?> toShortcutMemoryIcon(
+    String roomId,
+    DatabaseApi? database,
+  ) async {
+    final cacheKey = Uri.parse('im.fluffychat://shortcuts/$roomId');
+    final cachedFile = await database?.getFile(cacheKey);
+    if (cachedFile != null) return base64Encode(cachedFile);
+
+    final image = decodeImage(this);
+    if (image == null) return null;
+
+    final size = image.width < image.height ? image.width : image.height;
+    final x = (image.width - size) ~/ 2;
+    final y = (image.height - size) ~/ 2;
+
+    final croppedImage = copyCrop(
+      image,
+      x: x,
+      y: y,
+      width: size,
+      height: size,
+    );
+
+    final bytes = croppedImage.toUint8List();
+    await database?.storeFile(cacheKey, bytes, 0);
+
+    return base64Encode(croppedImage.toUint8List());
+  }
+}