improved performance and battery usage on older devices

lib/utils/screen_bound_image.dart

@@ -0,0 +1,25 @@
+import 'package:flutter/widgets.dart';
+
+/// Wraps [provider] so it decodes at most [scale] × the screen's longest
+/// physical side (capped at [maxPx]). Camera-sized photos otherwise decode at
+/// full resolution — 50–200 MB each — which gets the app killed on
+/// low-memory devices.
+ImageProvider screenBoundImage(
+  BuildContext context,
+  ImageProvider provider, {
+  double scale = 1,
+  int maxPx = 4096,
+}) {
+  final bound =
+      (MediaQuery.sizeOf(context).longestSide *
+              MediaQuery.devicePixelRatioOf(context) *
+              scale)
+          .round()
+          .clamp(1, maxPx);
+  return ResizeImage(
+    provider,
+    width: bound,
+    height: bound,
+    policy: ResizeImagePolicy.fit,
+  );
+}